Sadiq Khan questions George Osborne's ability to be both MP and editor Why BlackRock wants to pay George Osborne £650,000 a year | Nils Pratley

Sadiq Khan

The mayor of London, Sadiq Khan, has questioned whether George Osborne will be able to edit London’s Evening Standard newspaper while remaining an MP for his north-west constituency.

Khan had initially congratulated the former chancellor when his shock appointment was announced last month, but told the radio station LBC he now had reservations about whether the new role was compatible with Osborne performing his duties as MP for Tatton.

Osborne’s decision to continue in both jobs has been criticised both for the potential conflict of interest and the competing demands on his time.

Since leaving the Treasury, Osborne has also picked up four other roles: earning £650,000 a year as an adviser to the US investment firm BlackRock, chairing his Northern Powerhouse Partnership thinktank, academic work as a Kissinger fellow at a US university, and an after-dinner speaking contract with the Washington Speakers Bureau.

Khan, who quit as MP for Tooting when he won the London mayoral election said: “It’s a privilege to be a member of parliament. It’s really hard work if you’re a conscientious member of parliament. I can only do one job as an MP, to be an MP.”

Though Osborne’s defenders have argued being a newspaper editor would put less demand on his time than being chancellor, which he combined with his job as a constituency MP, Khan said it was not a fair comparison.

“Sure, you can be a minister because it complements your job as being an MP,” he said. “And that’s different from having a second job, whether it’s a company director, whether it’s editor of a newspaper, and so I wish George well. I couldn’t do it. I couldn’t be an MP and be an editor.

“And I also think, by the way, if you are going to be a member of parliament and take it seriously you should just do that one job properly.”

Osborne was sacked from his role at the Treasury after Theresa May won the Tory leadership in the aftermath of the EU referendum. During a trip to the Middle East this week, the prime minister defended his decision to take the Standard job, saying: “MPs throughout time and continuing now have often had other roles and responsibilities and jobs as well as being an MP.

“We have doctors, dentists, nurses; we have reservists, special constables in the House of Commons. That brings a breadth of experience into the House of Commons.”

Her supportive comments appeared to rule out removing the Tory whip from the former chancellor, which some MPs had urged to avoid conflicts of interest.

Osborne is set to take up his Evening Standard job on 2 May and has said he will edit the evening paper in the morning before heading to the Commons in the afternoon.