SCOTTISH Greens co-leader Patrick Harvie hit back at Robin Harper, the party’s first MSP, after his resignation was sent to "right-wing" media before party leadership.

In a leaked internal message seen by The National, Harvie said that Harper, who quit the Greens citing the party’s stance on independence and trans rights, was arguing a position with “very little credibility”.

Harvie said the former MSP’s intervention had come “after several years of detachment from the party's activism” – and questioned the key points from his resignation letter.

“While he describes himself as ‘left of centre’ ... you may share my surprise that he sent his resignation letter to a right-wing newspaper before he sent it to me,” Harvie wrote.

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Pre-warning Green activists ahead of the story’s publication in The Times, the Scottish Government minister said: “We can expect his resignation letter to be made public, and our critics to give insincere praise for Robin as the kind of Green they all miss – including the very people who derided him and everything about the Scottish Greens while he was in Parliament!”

Harvie went on: “In his letter Robin cites several issues. He opposes independence, though clearly this wasn't important enough to him to prevent him being a member and MSP for a pro-independence party for many years.

“He cites ‘the way we are handling the situation with the trans community’, but without giving much detail. This isn't the first time he has expressed disagreement with our support for trans people's equality, but I find it genuinely sad that he is unable to recognise our strong track record and principled stance on this issue.

“He criticises our lack of ‘willingness to cooperate’ with others, despite the fact that we have achieved a pioneering political cooperation agreement which has brought us into government.”

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Harvie (above) further urged Green members not to “engage in hostile discussion of this on social media”, adding: “I think it's fair to say that most serious political observers will recognise that Robin's position has very little credibility.”

He claimed that publicly rising to Harper’s criticism “would only benefit those who oppose the Green agenda and who hate the fact that we are both delivering on our policies and at a historic high point in the polls”.

After his letter went public on Wednesday evening, Harper spoke to the Daily Record and said he would vote Labour at the next General Election.

Harper has also been working with Gordon Brown’s dark-money think tank Our Scottish Future on Unionist efforts.

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A Green source told The National that news of Harper’s Labour affiliations came as little surprise, adding that they were “glad to see that he has finally resigned”.

“He has been an outspoken opponent to the party stance on trans rights for years,” they said. 

Harper served as the Greens’ first ever MSP and was a member of the Scottish Parliament after it was reconvened in 1999 until 2011.

In his resignation letter, he apologised for “not attempting to speak up within the party” about his reservations about its direction before resigning.

Harvie’s internal message ended by informing Green activists of the party’s official line which would be released to the media. This thanked Harper for his service to the Greens and the environment, but avoided confrontation.

The Greens declined to comment.