Veteran gay rights campaigner Peter Tatchell called on Glasgow 2014 organisers to ban nations that discriminate against athletes because of their sexuality or gender.

Officials have promised “an outstanding, athlete-centred and sport-focused” event come July.

But Mr Tatchell warned that prejudice may bar many athletes from competing at all.

He said he had written to the organising committee’s chief executive David Grevemberg to ask that competing nations sign a pledge not to discriminate in their team selection on grounds of “race, ethnicity, caste, gender, disability, faith or non-faith, sexual orientation or gender identity.”

The Games Federation’s constitution already covered non-discrimination, Mr Tatchell said, but many Commonwealth members treated it as “a mere formality.” Shockingly, 41 of 53 member nations had laws criminalising homosexuality, seven of which involved life imprisonment and three carrying a death penalty.

Meanwhile cultural attitudes of homophobia, biphobia and transphobia would “almost certainly” factor into selectors’ decisions unless instructed otherwise.

“The Commonwealth Games should foster a culture of equality where athletes compete solely on the basis of merit,” he said.