Boris Johnson’s leadership team have promised “no change” to how Scottish government funding is calculated if he becomes prime minister.
Jeremy Hunt had already pledged to “maintain” what’s known as the Barnett formula, and had challenged his rival to match his commitment.
Mr Johnson has long criticised the formula.
At one point he claimed it amounted to a multi-billion pound “present” from English taxpayers to Scotland.
One Hunt supporter, John Lamont MP, welcomed what he said appeared to be a “U-turn” by Mr Johnson.
Mr Hunt and Mr Johnson are competing against each other to become the next Conservative leader.
The Barnett formula is used to share funds across the UK with allocations for Scotland, Wales and Northern Ireland linked to their populations and any changes in spending in areas such as health and education in England.
It’s controversial because levels of public spending per head are higher in Northern Ireland, Scotland and Wales than they are in England.
Mr Johnson, a former London mayor, has been a persistent critic. In 2014, he said the then prime minister, David Cameron, had made a “slightly reckless promise” to retain it.
He had previously described the system as being of “amazing political antiquity” and producing “inequitable outcomes”.
The SNP were among those expecting Boris Johnson to review funding arrangements for the devolved governments if he became prime minister.
MSP Tom Arthur said: “With the hard right-wing of the Tory party threatening to axe the Barnett formula and slaughter Scotland’s public services it’s time to take our future into our own hands.”
But Boris Johnson’s campaign has indicated that the system will stay the same if he replaces Theresa May in Number 10.
A campaign source said: “There’ll be no change to the Barnett formula if Boris wins the leadership of the Conservative and Unionist Party and becomes prime minister.
“For the SNP to suggest otherwise shows a hitherto unseen level of desperation and underlines just how much they would fear a Conservative and Unionist Party led by Boris.”
The Hunt campaign had also questioned Mr Johnson’s commitment to existing funding arrangements.
Conservative MP John Lamont MP, who is a prominent supporter of Mr Hunt, said: “I’m pleased that despite what Mr Johnson has said in the past about reviewing the special funding arrangements for Scotland, he has now apparently u-turned on this policy.
“Jeremy Hunt has always been clear that he supports the continuation of the Barnett formula, no if, buts or U-turns.”