Michael Portillo finally broke his silence on Iain Duncan Smith's leadership of the Tory party yesterday, urging him not to take a leading role in a euro referendum debate.
In his first public comments about the man who defeated him in the battle to succeed William Hague last year, Mr Portillo warned that Mr Duncan Smith could seriously harm the "No" campaign against the single currency.
The former defence secretary also said that had he been elected leader, he would have made greater changes to Tory policy; in particular, selecting candidates who more accurately represented modern Britain.
The dual assault, which will infuriate some of Mr Duncan Smith's allies, came despite Mr Portillo's protestations that he did not want to be a "back-seat driver". Mr Portillo has been silent on the Conservative leader's strategy and performance in the 11 months since his own leadership bid failed, making only three speeches in the Commons.
Speaking on BBC1's Breakfast with Frost, Mr Portillo gave his strong backing to the views of Dominic Cummings, the Central Office director of strategy, who said earlier this month that the Tories were too unpopular to lead the battle against the euro.
Mr Cummings's remarks inThe Independent sparked a fierce row within the party about the role that Mr Duncan Smith should take in the referendum.
Mr Portillo said: "That advice has been coming from people leading the "No" Campaign, who have brought together a coalition of people and business people who don't want to see Britain going into the euro.
"Fewer people voted Tory last time than Labour, and therefore there might be people who are against the euro but don't want to be associated with the Tory party, so there is a problem there."
Mr Portillo added that he had felt "relieved" when he was knocked out of the Tory leadership contest last July, after leading the field early in the battle. "If I had won, I would have made big changes to the Conservative Party," he said.
"I really felt I needed a huge mandate and a real showing of support, and it wasn't there."