Polygamy in the United KingdomFrom Wikipedia, the free encyclopediaPolygamous marriages may not be performed in the United Kingdom, and if a polygamous marriage is performed, the already-married person may be guilty of the crime of bigamy.
Polygamous marriages legally performed in another country where the law allows it are not recognized for pension, immigration or citizenship purposes. However, they may be recognized for the purposes of welfare benefits. This decision was not made without controversy, and there have been protests against it. None the less, it is unofficially believed that there are up to 20,000 polygamous marriages in the Muslim community of the U.K. 
No comment necessary