Britain’s most senior Muslim MP has received death threats from some hardline Islamic extremists after voting in favour of equal marriage earlier this month.

Police have told Labour MP Sadiq Khan, who is also the shadow justice secretary and represents Tooting in south London, that he should review the security around him and his family following the Commons vote.

Some Islamic groups said that by voting for same-sex marriage, Mr Khan was “selling out” his religion.

Mufti Muhammed Aslam Naqshbandi Bandhalev, head imam of the Jamia Islamia Rizvia mosque in Bradford, issued a fatwa against Mr Khan declaring that he is an “apostate” from Islam who must “repent before Allah”.

The Daily Mail reports the MP told one friend that he was especially concerned about those close to him, saying: “My family do not need to suffer for what I have to do for my job.

“I’ve not had threats like this before.”

Inayat Bunglawala, of Muslims4UK, said: “It is deeply worrying to see that Sadiq Khan has been subjected to these sinister threats.

“He is a working-class Muslim from South London who has done well.

“Instead of vilifying him as an apostate, his short-sighted and bigoted detractors would do better by looking to him as a talented and hard-working role model for young Muslims.”

Mr Khan was among 400 MPs, five of them Muslim, who voted in favour of the Marriage (Same Sex Couples) Bill on Tuesday 5 February.

22 Labour MPs voted against the bill – and 16 MPs including Gordon Brown were not present for the vote; the former PM and Labour leader was on a pre-arranged trip to the US in his capacity as UN Special Envoy for Global Education.