Douglas Ross has urged SNP rebels to work with him to tear down the power-sharing deal at Holyrood between their party and the "extreme" Scottish Greens.
The Scottish Tory leader said it was time for a group of high-profile SNP MSPs disillusioned with environmental policies being pursued under the Bute House Agreement to "put up or shut up".
He said they could count on the votes of his party if they wanted to try and block the Greens' policy agenda at the Scottish Parliament, or attempt to destroy the coalition deal.
In a direct challenge to the group, he urged them to prioritise kicking "the Greens and their extreme policies out of government" over "blind allegiance to the nationalist cause".
Outlining his party's new strategy for increasing Scotland's sluggish economic growth, Mr Ross said they should accept his offer if they believed that Green policies were "damaging the rural livelihoods and communities they represent".
He also argued that next week's programme for government, Holyrood's version of Westminster's King's Speech, was Humza Yousaf's final chance to "step out of the shadow of his discredited predecessor".
Bute House Agreement
Nicola Sturgeon signed the Bute House Agreement with the Scottish Greens after the 2021 election, bringing them into government for the first time.
The Telegraph says a poll published last week found more Scots oppose the arrangement than support it following a raft of environmental policies targeting households, drivers and rural communities.
Kate Forbes, who narrowly lost out to Mr Yousaf in the SNP leadership contest, told an Edinburgh Fringe event that her constituents in the Highlands had "a sense of being preached at" about net zero.
She has argued that SNP members should be asked whether they still support the deal, while Fergus Ewing, a former Scottish government cabinet minister, has described the Greens as "hard- left extremists who should never be anywhere near government".
Mr Ewing warned the coalition agreement has left the SNP "tarnished, damaged and diminished" following the bungled attempt to set up a deposit-return scheme for drinks containers.
Many SNP politicians in the Highlands were deeply unhappy about plans to ban fishing in 10% of Scotland's seas before they were shelved, and remain frustrated at the slow pace at which the A9 between Perth and Inverness is being dualled.
Stances supported
SNP parliamentarians are also split over Mr Yousaf's decision to take court action to defend Ms Sturgeon's self-ID gender laws and his opposition to new oil and gas licences in the North Sea. Both stances are strongly supported by the Scottish Greens.
Mr Ross argued that the first minister was the Bute House Agreement's "most passionate supporter" and said the idea that the SNP would "willingly pull the plug on their nationalist coalition partners is for the birds".
He said most of the SNP rebels "were all too happy to collect a ministerial salary" by serving with the Greens in Ms Sturgeon's government "and despite their tough words they don't act".
For example, he said only Mr Ewing had backed a motion of no confidence in Lorna Slater, the Scottish minister responsible for the deposit-return scheme debacle.
"So I say directly to these would-be rebels that it is time to put up or shut up. If they want to challenge any part of the green policy agenda, then they will have the support of Scottish Conservative MSPs," Mr Ross said.
Scottish Conservative votes
"And if they want to vote down the Bute House Agreement, then they can count on Scottish Conservative votes."
He said a key test would come next month, with the Tories planning to force a vote backing a delay to the licensing of Airbnb-style short-term lets. Mr Yousaf has refused an extension to the October 1 deadline despite pleas from property owners.
Mr Ross added: "So let's see what these SNP rebels are made of. Are they going to put party loyalty and the drive for independence above small businesses who are going to the wall as a result of their policies?"