Iain Duncan Smith has launched a personal attack on David Cameron and George Osborne, suggesting they have lied to the public over the EU referendum and accusing them of having “lost faith in Britain”.

In an interview with The Sunday Times, the former work and pensions secretary described the government’s position as “false”, adding: “What is being sold to the British people by the government at the moment is nothing short of a sham.”

Duncan Smith resigned last month with an emotional outburst about Treasury plans to slash disability benefits. Yet last week he was in a cold rage with the leading lights of the “remain” campaign.

He said the prime minister’s decision to renegotiate Britain’s relationship with Europe, outlined in Cameron’s Bloomberg speech of