Former Green Party candidate and gay rights activist Peter Tatchell has called for Green supporters to vote for the Liberal Democrats in certain seats.

Mr Tatchell, who remains the party’s human rights and LGBT spokesman, told a Instigate debate last night in London that even people who usually vote Green should support incumbent Lib Dem candidates or those likely to succeed.

He told PinkNews.co.uk today that he was not a Lib Dem supporter but the party promises to change the “corrupt” voting system.

Mr Tatchell, who emphasised he was speaking in a personal capacity, said: “On May 6th, Labour could come third in the number of votes but still end up with the most seats. That is not democracy. The voting system is corrupt and has to change.

“The Greens support voting reform but the Lib Dems are the only major party committed to a fairer voting system.

“If they hold the balance of power, the Lib Dems will almost certainly ensure a fairer voting system which will be the single biggest democratic advance in Britain since the suffragettes.”

He added that he wanted people to vote Green in the party’s target areas, such as Brighton Pavilion, but urged everyone to vote Lib Dem where Labour or Conservative MPs could be unseated.

A Green Party spokeswoman said: “We don’t really agree with that, that is Peter speaking in a personal, individual capacity. That’s his opinion and not what we’d want to encourage from the party’s point of view.”

Mr Tatchell stood down as the Green candidate for Oxford East in December, saying that brain injuries sustained through years of campaigning meant he could not do the job.