The criticism concerns marriages that were entered into abroad before July 1 and which, according to the government's proposal, would be retroactively banned.
The Legal Council doubts that such a retroactive ban would counteract defamation of honor, which is one of the government's arguments.
"Instead, foreign spouses risk being hit by unexpected legal consequences that are, for an individual, difficult to investigate," writes the Legal Council, mentioning how it could affect the economy.
In addition, the Legal Council believes that it is inconsistent that a cousin marriage registered in Sweden before the new law came into force will continue to be valid.
The Legal Council therefore proposes that transitional rules be introduced.
