Claims made by Chancellor Philip Hammond that the Scots Tory bloc influenced his Budget have been disputed by the SNP.
Mr Hammond previously told the Commons that he had his “ear bent” by colleagues north of the border over VAT paid by police and fire services in Scotland.
But SNP MP Alan Brown (Kilmarnock and Loudoun) said he had spoken to the Chancellor’s office and no such meetings on VAT could be highlighted.
In his Budget speech, Mr Hammond said: “I am getting used to the new experience of having my ear bent by my 13 Scottish Conservative colleagues, most recently on the issue of Scottish Police and Fire VAT.
“So we will legislate to allow VAT refunds from April 2018.”
Mr Brown, speaking during business questions, told Commons Leader Andrea Leadsom: “In amongst the spin of how powerful the new Scottish Tories are and how they secured that £40 million VAT exemption for police and fire services, yesterday I actually highlighted they come at a cost of £265 million per Scottish Tory.
“If they genuinely did do so much work in terms of the VAT exemption can she make a statement outlining why the Chancellor was not able to give me in writing a date of one meeting with any one of the 12 backbench Tories on VAT exemption?”
Since 2013 the SNP claims some £140 million has been slashed from frontline services to make VAT payments.
The situation arose as policing and fire services in Scotland were previously controlled by local councils which can claim back VAT.
The new national forces are controlled by the Scottish government, which cannot.
Responding to Mr Brown, Mrs Leadsom said: “Can I say I am delighted that he recognised the amazing work done by my friends the Scottish Conservatives.
“I share his enthusiasm for their assiduousness towards looking after the interests of their Scottish constituents.
“I am sure he will be delighted as I am that in our Budget a couple of weeks ago the Chancellor was able to confirm a £2 billion consequential budget boost for the Scottish Parliament.”