Theresa May has been urged to apologise for Britain’s historical legacy of anti-gay laws across the Commonwealth as leaders of the 53 member states gather for a summit in London on Monday.

Gay rights campaigner Peter Tatchell argued that the government should help address colonial-era legislation that treats more than 100 million lesbian, gay, bisexual and trans people across the Commonwealth as criminals.

The prime minister went further than any of her predecessors when she acknowledged last year that Britain had a “special responsibility” to help change hearts and minds on anti-gay laws as a result.

The Guardian understands that the government plans to make an announcement on the issue at the heads of government summit later this week – but will avoid any grand political gestures that might prompt accusations of neocolonial lecturing.

Former prime minister David Cameron was criticised in 2011 when he told Commonwealth leaders at a meeting in Australia that UK foreign aid should become conditional on their decriminalisation of homosexuality.

Tatchell, a veteran campaigner, said: “I urge Theresa May to acknowledge and apologise for what Britain did by forcing homophobic laws on colonial peoples. These laws remain today and are menacing the lives of millions of LGBT people in Commonwealth countries.

“An apology would wrong-foot homophobes in the anti-gay member states by highlighting the nonindigenous nature of their current homophobic legislation.” Read more via Guardian