Will criticizing immigration be illegal in Sweden?
I believe not, that simply criticizing immigration will not be illegal:
- Because see What about 'free speech'? below.
Because I don't see (in the described change to the law) such a big change to the law.
Because for example the Sweden Democrats party have and will presumably continue to communicate their anti-immigration policy. They are legal and hold 14% of the seats in parliament:
The Sweden Democrats or Swedish Democrats (Swedish: Sverigedemokraterna, SD) are a far-right,[13][14][21][22] right-wing populist,[5][10] and anti-immigration[23][24][25][26] political party in Sweden that was founded in 1988.[27]
The Sweden Democrats continued this success in the 2014 general election, polling 12.9% and winning 49 (14% of) seats in parliament.[18] The party remains isolated and excluded from influence by all other parties in the Riksdag.[33]
The Sweden Democrats believe that the current Swedish immigration and integration policies have been a failure.[68][69] SD is the only party in the Swedish Parliament without an integration policy.[70][71] They oppose integration because etc.
Because the committee says that they aren't changing law about what's "free" versus "illegal" speech, they're only changing law to allow increased opportunity or public prosecution.
Summary of changes to the existing laws
The following is what was said in (or by, or to) Swedish Parliament about the "new law":
(I introduce some references as evidence and quote from them, below. The quoted text is auto-translated from the Swedish using Google Translate. Some of it has been edited by Swedes as mentioned in comments below.)
Cited references to these details
The news article which is referenced/questioned in the OP says,
Member of Parliament Andrew Norlén, member of the Constitutional Committee, has been pushing the issue and he says it will rapidly become a deterrent.
“I do not think it takes very many prosecutions before a signal is transmitted in the community that the internet is not a lawless country, the sheriff is back in town” Norlén said during a one-sided ‘debate’ on the issue in Swedish parliament.
Therefore that news article is referring to the following law, which Andreas Norlén introduced to Parliament in the following brief speech, which I quote below as follows in its entirety.
9 § Some changes in pressure press and the freedom of expression
Constitutional committee's report 2013/14: KU17
Some changes in pressure and the freedom of expression (Prop. 2013/14: 47)
was preferred.
Anf. 13 Andreas Norlén (M):
Mr President We in the constitutional committee is unanimous on this
report, which deals with some changes in pressure and the freedom of
expression. It contains proposals for constitutional amendments and
some other important legislative changes. There is therefore reason to
say anything about it in this House, although we totally agree.
I have a particular interest in the issue because I was a member of
the Freedom of Expression Committee, therefore, the government report
which presented the investigation report, which forms the basis of the
proposals we are now debating.
The aim of the key proposals which this report is to some extent
adapting Swedish legislation to the development of society that has
meant that the number of defamation offenses has increased
exponentially in our country in recent years.
The concept of defamation offenses sounds a bit archaic. It has an
archaic ring to it, but it involves conduct which constitutes a
painful reality for thousands of people in our country, not least for
many young people. I am thinking primarily on the gross violations
that every day affects many people on the internet in the form of
insults, slander, insult, and everything whatever it may be.
The development of the Internet has led to the tremendous
opportunities in terms of communication and new services. It has
changed our world for the better, but it has also brought
unprecedented opportunities for violations of other people -
violations that may very common and which often causes a lot of great
suffering.
A starting point in Swedish law is that the criminal libel, slander
and insult, it is the plaintiff - that the victims of the crime - to
prosecute. This will still be the starting point even after the
legislative changes we are proposing, but it introduces some
modifications.
It is quite obvious that the step for the person being insulted and
attacked on the Internet - even if there are serious violations - to
bring a private prosecution against the person who made these
observations are often very long. The vast majority of violations goes
obeivrade past.
Then, the problem is that respect for the rule of law and the rules
that are against slander and insult risk of erosion. The Internet is
not a lawless country. It applies the same rules and regulations about
how we should behave towards each other when we act on the internet
that when we act in the real world and not moving in the virtual
reality. Slander and also insult is just as illegal on the internet as
it is when you meet on the square. With these amendments, we give
public prosecutor little more opportunity to intervene and criminal
action rather than submit to the individual to make their case and
bring private prosecutions. To the public prosecutor to initiate legal
prosecution for defamation or insult, it has clean lagtekniskt
hitherto required to for specific reasons warranted in the public
interest. Now changed this so that the requirement for special reasons
deleted. Suffice it to say that it should be warranted in the public
interest. It involves some extension of the general prosecution law.
What could it be about? What could it be for societal interests that
are evident? Yes, that's if it's particularly serious violations or
violations may be particularly large spread, for example, that they
take place via the internet. But it can also be in the interests of
the individual, that is, the individual objective has been very hard
hit by deeds. There may also be a reason for criminal action.
The government also claims in the bill that the fact that a young
person is affected may be another reason for the public prosecutor
must intervene.
This is great changes. They make it a little better opportunities for
public prosecutors and police to intervene. I do not think that it
requires very few prosecutions before sending a signal to the
community that the internet is not a lawless country - the sheriff is
back in town, if you want to put it a little slängigt. I hope that
police and prosecutors are using the new opportunities and ensure the
prosecution of a number of criminal defamation on the Internet, in a
way that makes respect for the rule of law can be strengthened.
With that, Mr President, I call assent to the proposal in the report.
There's also a description of these to the law, in the following Constitutional Committee report on the Swedish Parliament web site, from which I quote a few paragraphs below.
Report 2013/14: KU17 Some changes in freedom of press and speech
The bill also proposed giving individuals a stronger procedural position of libel and increased protection for privacy. The Government proposes that the requirement in the Criminal Code on the specific reasons for the criminal action for defamation and insult is removed. This means that the prosecuting attorney and the attorney general will increasingly be able to assist individuals such as has been slandered on the internet.
The government also makes proposals which implies that the plaintiff should be able to avoid paying the opposite party in a pressure or freedom of expression when the plaintiff's action was dismissed but he or she has had particular reason to be tried.
The following is a description of the current law:
When it comes to prosecution for slander, coarse slander and insult are special provisions in Chapter 5. § 5, first paragraph Criminal Code. Under this provision, these crimes are not prosecuted by someone other than the plaintiff. In the case of defamation, rough defamation or certain types of insult - such as insult to anyone with allusion to his or her race, color, national or ethnic origin or religious belief - and the offense is against someone under eighteen years, or if otherwise the plaintiff states the offense, may prosecutor to prosecute if there for specific reasons deemed necessary in the public interest.
The new law is,
If a defamation crimes directed against someone who is under eighteen years of age or if the injured party in another case indicates the offense, the prosecutor would receive a prosecution if this is called the public interest and other conditions for prosecution are met. The Government's proposal means that the requirement for a special reason to prosecute these cases to be removed.
As reasons for the proposal, the Government states that, in particular Internet enabled a very large and rapid dissemination of information. The information is easily searchable and often remain on the internet for a long time. This is according to the government, of course, generally positive from the Freedom of Expression and Democracy perspective, but not when it concerns criminal messages such as slander. It can be assumed that the large and rapid spread, along with the fact that the data remains on the internet and are searchable for a long time, results in a different and more difficult consequences for those who consider themselves vilified than other more traditional publications. It has also recently been recognized that the climate in various discussion forums are hard and that many, especially young people, "hung out" on the web in a way that can affect them significantly.
Especially in the light of these developments, the Government considers, like the Committee, that there is reason to strengthen individuals' procedural protection when exposed to defamation or insult by the general somewhat greater extent than at present responsible for defamation offenses prosecuted criminally. Freedom of expression suggests that it should be done by the possibility of criminal proceedings for defamation and insult expanded. The Government agrees with the Committee's proposal. A slight extension of the possibility of public prosecutions allow inter alia something more intervention by public authorities against slander and insults on the internet. Such crimes are most common on websites that are not covered by the Freedom of Speech. The Committee, however, the changes apply not only to those sites but also on the constitutionally protected area and for slander and insults that take other forms.
Some of the respondents remarked that the proposal is likely to cause a greater caution in the media because of the increased risk of public prosecution and thus have a negative impact on freedom of expression. The Government believes that the media's concerns are based on the assumption that the public prosecution will be brought in more cases than before, which may lead to more convictions. Hence, the media is affected when making a decision about publishing or not. The Government considers that this concern should not be exaggerated. There is no question of an extension of the criminal area, but it is only about an increased opportunity for public prosecution. In this context it should also be noted that JK shall observe the so-called instruction, which according to the government means that one must assume that the JK will not intervene in cases other than when it is really justified.
What about 'free speech'?
The OP/question says, "The claim that one of the most developed of european countries would abolish freedom of speech seems very unrealistic", but I think that "freedom of speech" (as that is 'commonly understood') is a peculiar and mostly-American law (e.g. because of the First Amendment there). Many other countries including Sweden have laws against 'hate speech':
Sweden prohibits hate speech, and defines it as publicly making statements that threaten or express disrespect for an ethnic group or similar group regarding their race, skin colour, national or ethnic origin, faith, or sexual orientation.[58][59] The crime does not prohibit a pertinent and responsible debate (en saklig och vederhäftig diskussion), nor statements made in a completely private sphere.[60] There are constitutional restrictions pertaining to which acts are criminalized, as well limits set by the European Convention on Human Rights.[61] The crime is called Hets mot folkgrupp in Swedish which directly translated can be translated to Incitement (of hatred/violence) towards population groups.
I personally find it regrettable that "freedom of speech" is interpreted as "freedom to hate on people" (but who am I to criticize). It's currently easy to find web sites which appear to hate on immigrants to Sweden.
Sweden also has existing laws against 'defamation' (which I won't quote here: there are several of them).
What about 'democracy'?
Wikipedia says (I repeat),
The crime does not prohibit a pertinent and responsible debate (en saklig och vederhäftig diskussion), nor statements made in a completely private sphere.
So I suppose that a statement like the following from the article referenced in the OP,
Without freedom of speech there can be no democracy. If you are not allowed to say certain things then parties that support your ideas cannot exist and Sweden is at high risk of turning into a communist USSR-like country.
... is not necessarily true.
I say "not necessarily true" because other countries manage to have hate-speech laws, without being called "a communist USSR-like country" (except perhaps by the odd American: "Soviet Canuckistan").
Germany has a (legal) political party that's anti-immigration, notwithstanding also having anti-Nazi laws.