Livingstone blames Johnson for scandal involving deputy mayor

Ken Livingstone, the former London mayor, has accused his successor, Boris Johnson, of failing properly to vet his deputy, Ray Lewis, because he was "desperate" to hire him quickly.

Mr Lewis quit on Friday after his claim to be a magistrate proved to be untrue. It followed a series of allegations – all denied – of financial and sexual misconduct. His departure is embarrassing not just to Mr Johnson, but also to the Conservative Party.

Mr Livingstone, who served two terms as the capital's Labour Mayor, said officials at City Hall had prevented him from fast-tracking the vetting of staff. He said the scandal involving Mr Lewis showed that Mr Johnson's team "clearly hadn't done the basic checking". "I am amazed because I was always told by senior staff 'You cannot do this – you have to advertise the post'," he added."It used to take eight to 10 weeks to get someone employed. I think that in a desperate desire to do something quick, they just cut that out."

Church leaders said they had warned the Tories of claims that Mr Lewis took £41,000 from three parishioners when he was the vicar of St Matthew's Church in West Ham, east London.

The shadow Chancellor, George Osborne, defended both Mr Johnson and Mr Lewis. He said Mr Lewis, a former head of the Eastside Young Leaders Academy – an after-school facility for disafffected teenagers – had brought "insights" about tackling knife crime to his job as London's deputy leader.

Mr Osborne also denied breaching Tory rules by accepting a payment of up to £10,000 for a speech to the Institute of Directors' annual conference in Jersey. Conservative Party rules state that shadow ministers should not be paid for speeches linked to their portfolios. "I registered [the payment] in the proper way," Mr Osborne told the BBC.

*Kenneth Clarke, the former Tory chancellor, has said he would welcome a return to top-level politics as part of David Cameron's cabinet if the Tories won the next general election.