It comes after it emerged the party will contest fewer than ten of Scotland’s 59 seats in next month’s general election.
The party said it was targeting resources at key seats but opponents accused the pro-independence Greens – who pushed the Liberal Democrats into fifth place in last year’s Holyrood vote – of a “disservice to voters”.
Last month Tommy Sheppard, SNP MP for Edinburgh East, urged Greens not to stand in areas where they risked splitting the pro-independence vote by putting up candidates in seats that the Tories are actively targeting.
A letter received by STV suggests there will be no more than nine. To qualify for an election broadcast, a party must be standing in at least a tenth of the 59 seats in Scotland.
The Greens increased their representation at the Scottish Parliament to six MSPs in 2016 and returned 19 councillors at last week’s local authority elections.
Green MSP Ross Greer rejected claims last night the Greens were “standing aside” under instruction from the SNP, insisting the decision was a matter for local constituency parties.
But Scottish Conservative finance spokesman Murdo Fraser said the move made the party a “pointless presence in Scottish politics”. Mr Fraser said: “The propping up of the SNP is embarrassing and a complete disservice to their voters.
“Quite simply, they might as well not exist. If they are so determined to become the SNP, they should disband and merge with the Nationalists.
“It’s utterly regrettable that a party previously committed to issues like the environment has become nothing but a support mechanism for the SNP.”
Highlands and Islands Green Party convener James MacKessack-Leitch, who stood against Mr Roberston in Moray two years ago, indicated the party’s decision not to field candidates was politically motivated.
“At any normal election we would be proud to field candidates and run a positive campaign, however, this is no normal election,” he said.
“This general election has been called for naked party political purposes as the Tories attempt to crush Labour in England and Wales.
“This immature behaviour has no relevance in the Highlands and Islands, let alone Scotland or Northern Ireland, but will only serve to increase voter apathy and anger at the way politics is conducted in this country, at a time when there are far bigger issues at stake.”
A spokesman for the party said: “Green campaign teams around Scotland are focused on building on the progress we made in last week’s council elections including our breakthroughs in the Highlands and Islands, with our newly elected councillors determined to protect local services. By targeting resources in key constituencies, such as Glasgow North where Patrick Harvie will be our candidate, we can build on our strong support to win Scotland’s first Green MP, offering a bold alternative to the other parties.”
But Labour general election campaign manager James Kelly MSP said the move “makes a mockery of the Greens’ claims to be a credible party”.
Mr Kelly said: “Patrick Harvie has only decided to stand in Glasgow North himself in a desperate attempt to prove that he really isn’t just a backbench SNP politician – and now it emerges his party could stand fewer than ten candidates.”
Scottish Liberal Democrat deputy leader Alistair Carmichael said: “The independence obsessed Scottish Greens have once again shown that they are a wholly owned subsidiary of the SNP. Voters across the country don’t want a divisive second independence referendum. That’s why more and more voters are switching to the Liberal Democrats to stop the SNP.”
Greens co-leader Maggie Chapman had previously indicated the party would not stand against the SNP in Tory target seats. Last month Ms Chapman did not see candidates standing against Tory Scottish Secretary David Mundell, or in a neighbouring Berwickshire, Roxburgh and Selkirk constituency where the Conservatives came a close second to the SNP in 2015.