Sir Trevor Chinn, a former backer of Tony Blair, last night confirmed that he is to join Boris Johnson’s Mayor’s Fund as chairman.

The fund will tap big business to fund community projects with the aim of stopping disadvantaged children turning to crime.

Although Sir Trevor was knighted under a Conservative Government in 1990, he has donated money to Labour and was appointed to a government commission for five years while Mr Blair was in office.

A renowned philanthropist, Sir Trevor, 72, could easily have been asked to advise the London Mayor on transport issues. His career began in Lex Garages where he followed in his father’s footsteps and at 33 he was running the business. In 1999 Lex acquired RAC’s motoring services arm for £427 million, which led to Lex’s change of name in 2001 to RAC. He retired from the business after 47 years in 2003.

No 14 in The Jewish Chronicle’s 2008 Power 100 List, Sir Trevor conducts his business affairs and charitable work from a plush office overlooking Hyde Park. He is a senior adviser to CVC Capital Partners, the private equity company, and nonexecutive chairman of Streetcar, the UK’s largest pay-as-you-go car club.

Sir Trevor, who is married with two children, said last night that although London was the richest city in Europe, it had appalling problems of overcrowding, unemployment, homelessness and child poverty.

In his new role, he joins Bob Diamond, the president of Barclays, head of Barclays’s investment arm and highest-paid FTSE 100 boss, who is an ambassador for the Mayor’s Fund.

The other trustees are Lesley King-Lewis, a former Barclays executive and joint chief executive of Action on Addiction, Stanley Fink, non-executive deputy chairman of hedge fund manager Man Group plc, music industry fundraiser Wasfi Kani and Sir John Beckwith, who established the successful real estate company, the London and Edinburgh Trust PLC.