Johnson calls for tax cut for top earners

Boris Johnson delivered a provocative challenge to David Cameron and George Osborne yesterday to cut income tax for Britain's highest earners.

The Mayor of London's call came after he burnished his Tory leadership credentials with an assured and joke-studded speech received rapturously by the party faithful. Although he was careful to praise Mr Cameron, he cemented his position as the Prime Minister's leading rival with a passionate plea for Britain to head into a new "age of enterprise" and a list of his achievements running the capital.

Later he reached out to the party right by repeating his demand for the top rate of tax to be lowered – although he acknowledged it would be "politically very difficult to deliver now" and "would not be easy at a time people are suffering".