The decision comes after he faced severe criticism over a failure to support free school meals for poor children south of the Border.
The group of six Scottish Tory MPs in Westminster will no longer cast a vote if the policy “relates to England only”, and any issues which have potential financial consequentials for Scotland will now be “analysed at the time”.
The sudden decision to formally change the voting policy of Scottish Tory MPs came in the wake of criticism of Mr Ross, who abstained on a Labour motion last week that would have seen free school meals delivered to poorer children in England during the school holidays.
The Moray MP said he did not take part in last Wednesday’s vote because he was in Scotland and could not get a proxy. None of the five other Scottish Tory MPs voted for the Labour motion.
However, while the Prime Minister has refused to back free school meals outside term time, Mr Ross has supported the move in Scotland. He previously resigned as a junior minister from the Johnson government after Dominic Cummings' defence of his trip to County Durham during the coronavirus lockdown.
Mr Ross is also close to Ruth Davidson, who was known to have clashed with Mr Johnson over Brexit, and aims to join her in the Scottish Parliament. But insiders say that growing support for Scottish independence is of huge concern to both, and there are fears the row over free school meals in England, added to concerns about the impact of Brexit, could provoke a backlash against their party in next year's Holyrood elections.
The decision by the Scottish Conservative leader was revealed after he was challenged by the SNP if he would vote for a second Labour motion to secure holiday-time free school meals, which has received widespread support after being spearheaded by England footballer Marcus Rashford.
SNP Westminster deputy leader Kirsten Oswald said Mr Ross needed to "salvage his credibility”, support free school meals in a second vote “and order his MPs to do the same”.
The SNP broke its own long-standing tradition of abstaining on votes not affecting constituents north of the Border, five years ago when it returned 56 MPs to the Commons.
A Scottish Conservative spokesperson said: “The Scottish Conservatives support the campaign by Marcus Rashford, which has been hugely inspirational. The UK Government must take it into serious consideration and listen to the wide range of voices in support of this policy ahead of any future vote. In future, our MPs will not take part in votes that relate to England only.”
He added: “However, we urge the SNP to bring forward a vote in the Scottish Parliament to implement the policy of free breakfast and lunches for primary pupils.”
The Scottish Government has committed to offering free school meals for children who qualify throughout the holidays.
Ms Oswald said: "Douglas Ross completely failed his first test of leadership on this issue by ducking the vote, while all of his Scottish Tory MPs voted to scrap free school meals. .”