A gay rights charity has called for “rational debate” in the conversation around gender identity as it holds its first annual conference.

The LGB Alliance said rights of lesbian, gay and bisexual people are “under threat” in the face of a campaign to replace sex with gender.

The organisation, which describes itself as standing for the rights of same-sex attracted people, said there is currently “so much acrimony” in the debate.

Guests at the all-day event are expected to include SNP MP Joanna Cherry, Conservative MP Jackie Doyle-Price, Labour MP Rosie Duffield and comedy writer Graham Linehan.

Ahead of the conference, LGB Alliance co-founder Kate Harris said: “LGB rights are once again under threat, in particular from the campaign to replace sex with gender. If we cannot define our own sexuality, it is impossible for LGB people to talk about our rights.

“There is so much acrimony in this debate but LGB Alliance firmly believes that rational debate is the only way forward. We can’t solve these complicated and important issues on social media or by simply pretending that conflicts of rights do not exist.

“Our message is simple: we need to talk. And that’s what we’re doing. We have assembled the biggest gathering of experts in this debate and we look forward to a lively and invigorating conference.”

Three demonstrators gathered outside the centre, holding placards saying “Trans rights are human rights”.

Kel Finan-Cooke, of the group Pride in Surrey, accused the LGB Alliance of being “an exclusionary organisation” and said the conference had been organised “to exclude the trans community”.

Last month, Ms Duffield reportedly accused party colleagues of “chucking me on the railway tracks” over her stance on issues such as people being allowed to self-identify as female and comments including “only women have a cervix”.

She stayed away from the Labour conference because of the abuse she suffered after being labelled a “transphobe”, but spoke at an unofficial fringe event.

Attendees at the Queen Elizabeth II Conference Centre in London on Thursday were asked to show proof of vaccination or a negative Covid test.