According to William E. Pomeranz of the Wilson Center:
the Minsk accords call on Kyiv not only to recognize the independence of Donetsk and Luhansk within the country but also to give these two regions veto power over any national legislation. Such authority would mean that Russia could effectively gain control over Ukraine’s internal politics.
But looking at Wikipedia's rather lengthy page on the accords, I don't see where veto power (by LPR/DPR) over "any" legislation is mentioned. The accords do explicitly provide for quite a few things, including LPR/DRP armed militias, limits the reach of Ukrainian law in LPR/DRP (effectively giving supremacy to the local decisions), and simultaneously obliges Ukraine to economically support these regions. But I don't quite see how it goes further than that, i.e. how it would have given LPR/DPR veto power in "any" national legislation. So how can one infer such a result from the Minsk accords?