THE Scottish Greens should strike an agreement with the SNP at the next Holyrood election to allow the bigger party to fight certain marginal seats – including Ruth Davidson’s Edinburgh Central – as the sole independence party, Tommy Sheppard has said.

He argued that if the Greens hadn’t stood in the constituency Davidson would not have taken it in 2016.

The MP for Edinburgh East believes enough of the 4644 votes given to the Greens’ Alison Johnstone would have gone to the SNP candidate to deprive Davidson of her majority – 610 votes.

Davidson took the seat from the SNP after its MSP Marco Biagi, a government minister, stood down to pursue a new career in academia.

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The SNP’s Alison Dickie came second, while Labour’s Sarah Boyack was third, while the Greens were fourth.

“I appreciate it’s a big ask and I don’t think the Greens should do it in all circumstances.

“But I think it’s important for people to think tactically and I think there are a few seats – and Edinburgh Central is definitely one – where the existence of a Green candidate allowed the Tories to win in 2016,” he told the Sunday National.

“If the Greens hadn’t stood last time there are over 4000 votes that would have gone somewhere else ... I am pretty sure that the SNP candidate could have got a lot more than 600 votes out of those 4000 Green votes than the Tory candidate would have. So end of.”

He added: “I know it might seem unfair as it’s always the smaller party which is asked to make this consideration. I say this with complete respect for the Greens and I know it’s a big ask but they have a couple of years to think about it. There are other areas where they could put their energy to much greater effect.

“What is the point in spending time and activist effort fighting a seat that you know you are not going to win if there is a serious and real chance of the Tories getting it because you split the vote?”

The Greens stood just three candidates in the 2017 snap election – in Glasgow North, Falkirk and Edinburgh North and Leith. However, by doing so it was accused by the Tories and Labour of being subservient to its “SNP masters”. The Greens said it had made the decision for financial reasons having just spent resources fighting the local council elections.

The party, led by Patrick Harvie and Maggie Chapman, had 32 candidates in the 2015 General Election but failed to win any seats. They currently have six seats at Holyrood.

A spokesman for the Scottish Greens​ said: “Our local members decide what seats we contest in a General election, and that will continue to be the case.”

The prospect of an electoral pact between the SNP and the Scottish Greens is likely to be a major issue ahead of the 2021 vote.

Some opinion polls have raised fears the current pro-independence majority at Holyrood could be lost – scuppering the chances of a new referendum on independence post-2021.

The First Minister’s request for a Section 30 order to allow Holyrood to legislate for a new vote on independence was rejected by Theresa May following the EU referendum, in which Scotland voted to remain but the UK overall voted to leave.

Nicola Sturgeon has said she will set out plans for a second independence referendum once there is clarity over the Brexit process.