George Osborne will be “more effective opposition” to the government as editor of the London Evening Standard than Labour under Jeremy Corbyn, the paper’s owner said.
Evgeny Lebedev defended his surprise choice for the role after criticism of the appointment from Labour and Conservative ranks.
The former chancellor is facing pressure to stand down as the MP for Tatton, in Cheshire, amid claims of “conflicts of interest”.
He also faces questions from constituents over the time he will be able to dedicate to the job, given his five other paid and unpaid roles.
Lebedev said on Twitter: “Sad old commentariat. Wait and see his paper before judging.
“Frankly George Osborne will provide more effective opposition to the government than the current Labour Party.”
Labour has called for an inquiry into whether he broke rules by failing to clear the appointment with the official watchdog which vets new jobs taken by senior public figures.
Shadow minister Andrew Gwynne has written to John Manzoni, permanent secretary at the Cabinet Office, asking him to investigate whether Osborne had breached the ministerial code of conduct.
In his letter, he said Osborne was required to refer any new job he intended to take within two years of leaving office to the Advisory Committee on Business Appointments (Acoba) before accepting it.
“The rules on business appointments are established to counter suspicion that the decisions and statements of a serving minister might be influenced by the hope or expectation of future employment with a particular firm or organisation, and that an employer could make improper use of official information to which a former minister has had access,” he wrote.
Labour MP Clive Lewis said he would be writing to Acoba directly about the appointment. “There are really serious questions about conflicts of interest,” he said.