Human rights campaigner Peter Tatchell has called on Prime Minister David Cameron to speak out against homophobia and declare his support for non-discrimination.
Mr Tatchell has previously written to the organisers of the Games, which start next Wednesday, urging them to ensure all member countries competing in Glasgow pledge their commitment to Article 7 of the constitution of the Commonwealth Games Federation.
This states that “there shall be no discrimination against any country or person on any grounds whatsoever, including race, colour, gender, religion or politics”.
In 42 of the 53 Commonwealth countries, homosexuality is a criminal offence, the Peter Tatchell Foundation said, with penalties of up to life imprisonment in at least seven member states and the death penalty in parts of northern Nigeria and rural Pakistan.
Mr Tatchell said: “Given the extreme homophobia and transphobia in most Commonwealth countries, it is very unlikely that most national selection committees would allow a lesbian, gay, bisexual, transgender or inter-sex [LGBTI] athlete to compete at Glasgow.
“David Cameron can help by making clear that such discrimination is incompatible with Commonwealth Games values and rules.”
Mr Tatchell said he wanted the Prime Minister to “give a lead and set a positive tone by publicly declaring that anti-LGBT persecution is a violation of the Commonwealth Charter and that LGBTI athletes will be welcome in Glasgow”.
The rally at Downing Street was organised by the African LGBTI Out and Proud Diamond Group.