Boris Johnson's referral to a police watchdog over claims a businesswoman received favourable treatment when he was London mayor is "clearly political", a cabinet minister has said.

Supporters of the embattled prime minister have questioned the timing of the move ahead of the Tory Party conference in Manchester and as he seeks to press ahead with Brexit in the face of stiff opposition.

The Independent Office for Police Conduct (IOPC) has been asked to assess whether Mr Johnson should be investigated for the criminal offence of misconduct in public office.

It follows claims that US entrepreneur Jennifer Arcuri received public money and privileged access to foreign trade missions while Mr Johnson was mayor.

Environment Secretary Theresa Villiers told Sky News that the complaint against the PM was "driven by political motivations".


She said: "The prime minister has said that all proprieties were observed in the normal way.

"I think the motivation behind the complaint is clearly political. This complaint is just a distraction from the important issues we face as a country."

But this was rejected by Jeremy Corbyn, who insisted it was not a case of political opportunism.

The Labour leader told reporters: "A wholly independent assessment has looked at evidence of the payments made by the mayor's office to one particular company and says there are serious questions to answer.

Johnson dodges questions on Arcuri claims

"I think the job of the prime minister is to answer those questions.

"When you hold public office, and you're also the police commissioner for London, you've got to be very careful about how you spread that public money out.

"He's given it to a company that has questions to answer and I think the prime minister should agree now and co-operate with the Greater London Authority inquiry."

In a statement, the Greater London Authority (GLA) said a "conduct matter" had been recorded against Mr Johnson.

The GLA added: "A 'conduct matter' exists where there is information that indicates that a criminal offence may have been committed.

"It does not mean that this is proved in any way. The IOPC will now consider if it is necessary for the matter to be investigated."

The matter has been referred to the IOPC, which handles complaints against police forces in England and Wales, because Mr Johnson held a post equivalent to a police and crime commissioner.

A spokesperson for the current London Mayor Sadiq Khan, who heads the GLA, rejected claims the referral was a politically motivated attack on the PM.

They said: "This process is nothing to do with the current Mayor whatsoever. It is a decision by the independent monitoring officer for the Greater London Authority."

Shadow chancellor John McDonnell tweeted in response: "It's important to note that this was a decision by the GLA monitoring officer, who is a completely, independent non-political official."

Ms Arcuri, a technology entrepreneur, was given a total of £126,000 in public money and privileged access to three overseas trade missions led by Mr Johnson, according to a report in the Sunday Times.

The newspaper said Ms Arcuri received preferential treatment to ensure she could come on trade delegations and Mr Johnson's team ensured she would accompany him on trips even though her initial applications to take part were refused.

The government has since frozen a £100,000 grant to Ms Arcuri's company, Hacker House, pending a review.

Mr Johnson denies any wrongdoing.

He has previously said that he will co-operate with any London Assembly investigation into his links with Ms Arcuri.