In a sign of growing tensions at senior levels of the Conservative party, the work and pensions secretary called on the prime minister to “play the ball, not the man”.
Duncan Smith also urged Cameron to reverse a new ruling that has banned civil servants from showing official papers related to the EU referendum to ministers campaigning to leave.
In a move aimed specifically at Duncan Smith, Sir Jeremy Heywood, the cabinet secretary, issued new guidelines last week to ban civil servants from preparing new research for anti-EU cabinet ministers that could be used in the EU referendum campaign.
The work and pensions secretary spoke out after the prime minister made a highly personal attack on Boris Johnson in the House of Commons last Monday.
Cameron suggested that the mayor of London had decided to campaign to leave the EU as a way of boosting his chances in the Tory leadership contest.
Johnson said he was unbothered by the attack, but he is now planning to play an even greater role in the EU referendum campaign. Anti-EU campaigners told the Sunday Times they were prepared to unseat Cameron even if he won the referendum, unless he ends “blue on blue” attacks.
Speaking on the Andrew Marr Show on BBC1 on Sunday, Duncan Smith advised Cameron to focus on the issues and to step back from personal attacks. He said: “The prime minister deserves some credit. This is a generous offer to let cabinet ministers break ranks and debate this because it is the biggest issue. But the general view at the time and I think should remain now is don’t play the person, play the ball. We should take a deep breath and ask ourselves a simple question. This is about Britain not us.”
However, he accused the prime minister and George Osborne of talking down Britain after they issued a series of warnings about the threat to the economy if the UK voted to leave the EU.
“I say this to those who want to remain in: I have never heard such a lot of pessimistic downsizing of Britain. Britain is a phenomenal country, the fifth largest in the world. It has stood alone and fought for freedom, it has traded, it has been a global trader. It can yet again be a global trader. Why would we have such a low opinion of the British people that we go out and talk about leaping into the dark, we talk about profound shocks? We talk about being too small. I have a different view. Britain is a great country.”
Duncan Smith added: “The in campaign’s whole strategy seems to be about, oh it is terrible, hang on to nurse for fear of something worse. It has been about saying we are too small, we are too little, we are too inconsequential. We can’t do what we want. I don’t know why anybody would want to run a country like this.”
He also said Cameron should reverse Heywood’s ruling. The move was intended to prevent Duncan Smith, who has strong doubts about the welfare elements of the prime minister’s EU reform plan, from asking his officials to assess the credibility of the plan.
Duncan Smith said: “I think that this can’t possibly apply in the sense of not knowing what is going on in the department because we are responsible for the departments. For example I will have to work on these proposals that came back from the recent renegotiations. If we vote to remain in we will have to deliver that.”
He said the welfare changes, including an emergency brake to restrict EU migrants’ access to in-work benefits for four years and to index child benefit to the cost of living in a migrant’s home country, could be delivered with difficulty.
“If we are asked to deliver it the department I have been running for five years I know has the skill and the capability to find a way to deliver it. It is not easy, it is not simple and it is complicated and it was not our proposal. It was the EU’s complex proposal but they could deliver it,” Duncan Smith said.
A Downing Street spokeswoman said: “There is no ban on ministers who support Leave receiving government papers. Day-to-day EU business will continue to be conducted in the usual way and all ministers will retain access to any papers relevant to their departments.
“It is only papers specifically relating to the EU referendum that they will not receive and that reflects the fact that the government has taken a position and they are choosing to take a different one.”
This article was written by Nicholas Watt Chief political correspondent, for theguardian.com on Sunday 28th February 2016 11.46 Europe/Londonguardian.co.uk © Guardian News and Media Limited 2010