Justice for Gay Africans says the new Commonwealth Charter – due to be signed by the Queen shortly – lacks teeth when it comes to protecting LGBT rights throughout the Commonwealth.

To mark Commonwealth Day, the Queen will sign a new charter on Monday evening which supporters claim backs equal rights for women and gay people in every Commonwealth nation.

It declares: “We are implacably opposed to all forms of discrimination, whether rooted in gender, race, colour, creed, political belief or other grounds.”

The words “other grounds” have been interpreted as including sexuality.

While Ben Summerskill, chief executive of Stonewall, said the Queen had taken “an historic step forward” on gay rights, several other LGBT activists including Peter Tatchell and the journalist Patrick Strudwick are dismissing the idea that the 86-year-old monarch has suddenly adopted a new position on LGBT equality.

Peter Tatchell said: “In her 61 years on the throne, the Queen has never publicly uttered the words lesbian or gay. She is a patron of hundreds of charities but none of them are gay ones. Never once has she visited or supported a gay charity.

In truth, the Commonwealth Charter does not include any specific rejection of discrimination based on sexual orientation. This was vetoed by the homophobic majority of member states.”

Godwyns Onwuchekwa, the chair and co-ordinator of Justice for Gay Africans said: “JfGA views this Charter, in its reliance on ‘other grounds’ to integrate protection against homophobia and gender identity based violence, as extremely limited it its ability to address this clear and contemporary area of concern, which includes extreme discrimination, torture, death, unjust imprisonment, and disregard for individual dignity and human rights. It is for this basic but crucial lack of specificity that we, with deep regret, reject the Charter’s revision as a missed opportunity.”

Mr Onwuchekwa added: “We call on the Commonwealth and its members to affirm protection for sexual and gender non-conforming (SGN) people in the Commonwealth with a guarantee to their dignity and personal respect. We are dismayed by media coverage in the UK and elsewhere that suggests that the Charter contains anything realistically useful for SGN people.”

Earlier on Monday, the Queen pulled out of the Commonwealth Day service at Westminster Abbey, on the advice of her doctors following her recent bout with gastroenteritis.

She will be seen in public this evening when she signs the new Commonwealth Charter and delivers a short speech.

41 of the 54 Commonwealth countries still criminalise homosexuality. Six of these countries name the punishment as life imprisonment, including Bangladesh.