Rishi Sunak has been urged to suspend the whip from the pensions minister over claims he used taxpayers’ money on Tory campaigning.
The MPs’ expenses watchdog said it has referred allegations about Paul Maynard, who was made a minister in the Department for Work and Pensions in November, to its compliance officer.
The Blackpool North and Cleveleys MP is alleged to have broken the Independent Parliamentary Standards Authority’s rules by charging taxpayers when producing political materials.
He is also alleged to have claimed rent for an office that doubles up as his local Conservative association’s headquarters.
The Liberal Democrats called on the Prime Minister to suspend the Tory whip from Mr Maynard and remove him as a minister while “these extremely serious allegations are investigated”.
Labour said “any suggestion that taxpayer money has been misused must be thoroughly investigated”.
Responding to the report in the Sunday Times, an IPSA spokesman said: “We will be referring this matter to IPSA’s compliance officer.”
The watchdog, which was set up after the 2009 MPs’ expenses scandal, said it would be up to the compliance officer to establish the facts of the case before deciding whether to conduct an investigation into the claims.
Mr Maynard said: “I have financial agreements in place with IPSA over the ad-hoc use of my constituency office by the local Conservative association.
“I believe that these arrangements are appropriate, but will be seeking clarification from IPSA to ensure this is the case.
“I will, of course, abide by any findings they make and ensure that any payments deemed necessary can be made promptly.”
Daisy Cooper, the Lib Dem deputy leader, said: “Rishi Sunak must suspend the whip and Paul Maynard as a minister whilst these extremely serious allegations are investigated.”
