It comes after Labour demanded a probe amid the allegation the former Conservative attorney general appeared to use his Commons office to conduct work outside his parliamentary duties.
It also emerged the Tory MP – one of the Commons wealthiest – voted via proxy from the Caribbean in April while it was claimed he missed more votes this week as he was on the island of Mauritius.
Facing intense scrutiny in the midst of a wider row over sleaze in politics, Sir Geoffrey, who has earned millions in addition to his salary as an MP, issued a defiant statement on Wednesday, insisting he did not believe he had broken any rules and would co-operate with any investigation.
According to the Daily Mirror, the Tory and West Devon MP also rents out a flat in Battersea, south London, which he bought as a second home with his wife for £535,000 in 2004, before joining parliament the next year. He then claimed £82,298 in expenses for mortgage interest payments over a period of four years.
After rules were tightened in the wake of the expenses scandal, the newspaper said he continued to use the property, but claimed only for utility bills and service charges.
But in 2017, Sir Geoffrey reportedly moved to another property in the capital and has charged the public purse £1,900 per month for accommodation, according to the latest figures available.
Despite the arrangement being within the Commons rules, the former standards committee chair, Sir Alistair Graham, told the Daily Mirror: “If they [MPs] have got a flat in London they should be happy enough to use that rather than go through this device to gain somewhere else and build up extra income.”
He also criticised the former Tory attorney general for claiming rent while working in the Caribbean, saying: “If MPs are out of the country and in the case of Mr Cox earning vast sums of money then to be at the same time claiming money from the public purse is totally wrong.”
A spokesperson for Sir Geoffrey’s office said: “The flat was purchased in early 2004, prior to Sir Geoffrey’s election to Parliament. While he claimed mortgage interest payments until 2010, fully in accordance with the rules, thereafter they ceased to be paid by Parliament. The flat was let out from late 2017 as declared in the register.”
According to a separate Guardian analysis, the former Tory attorney general earned at least £6 million in addition to his Commons salary since he became an MP in 2015.
Speaking on Wednesday, Boris Johnson declined to directly criticise Sir Geoffrey, but reminded MPs of the rules and was forced to deny that Britain was “not a remotely corrupt country” amid heightened scrutiny on MPs’ second jobs and a politically toxic row over sleaze in politics.
Paul Scully, the business minister, also refused to defend the Tory MP for voting by proxy from the British Virgin Islands and said the sleaze row had been “regrettable”.
“I’m not going to defend Geoffrey or say anything – that’s up to Geoffrey, it is between him and his voters,” he told Sky News on Thursday.
Quizzed on whether he could see the “optics were not good” in relation to the second jobs debate, Mr Scully replied: “Absolutely, I can see how it looks. It is really regrettable that we’ve got to this situation.”
A statement issued on Sir Geoffrey’s website yesterday, said: “He fully understands that the matter has been referred to to the parliamentary commissioner and he will fully cooperate,” in reference to the alleged use of his parliamentary office for a second job.
“He does not believe that he breached the rules but will of course accept the judgment of the parliamentary commissioner or of the committee on the matter.”
The statement also revealed that the party’s chief whip had advised him it was “appropriate” to vote via a proxy from the Caribbean in April while advising the government of the British overseas territory on a corruption case.