Human rights campaigner Peter Tatchell has slammed gay lobby group Stonewall for refusing to campaign for marriage equality.
During a meeting at the Liberal Democrat party conference on Monday night, the charity's chief executive, Ben Summerskill, claimed the organisation would not fight on the issue due to monetary matters.
He claimed it would cost the taxpayer £5 billion.
"Although Stonewall does a lot of valuable, important work, on this issue it is wrong," said Tatchell.
"It is, in effect, actively undermining the campaign for marriage equality.
"While many straight politicians now support same-sex civil marriage, Stonewall is refusing to campaign against the homophobic ban on gay and lesbian couples getting married. Among other reasons, it says equal marriage rights could cost £5 billion to implement.
"It is shocking to see a gay equality organisation declining to support equal rights legislation because it might cost too much. No other equality organisation makes equal human rights contingent on the cost. It is deplorable to insinuate that we can only have equality if it doesn't cost too much.
"Where does Stonewall get this £5 billion figure from? If civil marriage and civil partnerships are the same, as Stonewall has always claimed, how could marriage equality cost more? Every other comparable LGBT organisation in the world is campaigning to end the ban on same-sex marriage, but not Stonewall. It is out of step with the British and global trend towards equal marriage rights."
