Jeremy Corbyn is teaching Shadow Chancellor John McDonnell how to be a 'nicer person'

John McDonnell said the new Labour leadership will herald a 'kinder form of politics' and revealed Jeremy Corbyn is 'teaching me to be a nicer person'

John McDonnell will argue for steep tax rises on companies (Corbis)

Jeremy Corbyn is teaching his controversial and divisive shadow chancellor John McDonnell how to be a “nicer person”.

The appointment of his loyal friend and campaign manager was an indication that Mr Corbyn will go ahead with a radical, socialist agenda as leader and has not been a popular choice with Labour MPs and even members of the shadow cabinet.

MPs say he is an uncompromising politician who still pursues class battles from the 1970s and 80s. Having described "fermenting the overthrow of capitalism" as a hobby, joking how he wish he could go back in time to assassinate Margaret Thatcher and wanting to impose a 60 per cent rate of tax on the rich, it's not hard to see why.

But speaking on BBC's Question Time, Mr McDonnell said Mr Corbyn's election as Labour leader will herald a "new politics" and "a kinder form of politics, where you respect the other person's point of view".

Asked whether this would also apply to his own style of politics, he revealed: “I think Jeremy is teaching me to be a nicer person."

He took the opportunity on last night's show to apologise for saying in 2003 that IRA members should be "honoured" for their "armed struggle" and for his remark about assassinating Lady Thatcher, admitting it was "an appalling joke" that has "ended my career in stand-up".

Mr McDonnell's appointment as shadow chancellor did not win the full endorsement of other members of the shadow cabinet.

Asked whether he backed the move, shadow foreign secretary Hilary Benn simply said it was "the choice that Jeremy has made... I respect the choice that Jeremy has made as leader" when interviewed hours after the announcement.

His front bench colleague Kerry McCarthy, the new shadow environment secretary, said she and her colleagues would not allow Mr McDonnell "to dictate to the entire party" on the economy, insisting there was "a discussion to be had" about the party's economic policies.

She added: "What is our economic policy? I certainly don't know yet."