Theresa May met with a controversial pastor who campaigned against LGBT equality legislation during a church service she attended on Sunday.

The prime minister spoke at a question-and-answer session and met members of the Jesus House church led by pastor Agu Irukwu – a visit that human rights campaigner Peter Tatchell told BuzzFeed News is "an insult to black LBGT people".

In 2006, Irukwu was part of a group of pastors who wrote to the Daily Telegraph to express their opposition to the the Equality Act (Sexual Orientation) Regulations – a piece of legislation that aimed to make discrimination based on sexual orientation illegal.

"The latest discrimination against Christians is the new law called the Sexual Orientation Regulations, said to combat the problem of homophobia in Britain," the letter said.

"It alarms us that the Government's only evidence for a problem actually existing is 'accounts in national newspapers'. The regulations force Christians in churches, businesses, charities and informal associations to accept and even promote the idea that homosexuality is equal to heterosexuality.

"For the sake of clarity, this is not what the Bible teaches and it is not what we believe to be the truth. In our view, these regulations are an affront to our freedom to be Christians. If the government thinks that we will accept this law lying down, they are mistaken."