Iain Duncan Smith has been accused of cynically resigning because of the European referendum campaign rather than disability benefits by a minister in his own Department for Work and Pensions.

Ros Altmann, the pensions minister, launched a withering attack on her former colleague, who she said had tried to silence her. Lady Altmann claimed Duncan Smith had been “exceptionally difficult to work with” and was trying to inflict “maximum damage on the government.

“As far as I could tell, he appeared to spend much of the last few months plotting over Europe and against the leadership of the party and it seemed to me he had been planning to find a reason to resign for a long time,” she said.



The former Tory leader’s resignation on Friday came hours after sources at the Treasury indicated an imminent u-turn over the plans to change the assessment criteria for personal independence payments (PIP) for disabled people, leading to cuts of about £1.3bn a year.

The rumours in Westminster that the proposals were about to be kicked into the long grass may have been attempts to persuade Duncan Smith to stay in his post, though it would not have been long before the now former secretary of state would have had to have found a way for near-equivalent cuts for working age benefits.

Altmann said she was extremely shocked by the news of the resignation and was highly critical of the way Duncan Smith had behaved.

“Having worked alongside him as a minister in the Department for Work and Pensions, I have seen that he championed the very package of reforms to disability benefits he now says is the reason he has resigned,” she said.



“I simply cannot understand why he suddenly chose to quit like this when it was clear that No 10 and the Treasury had told him they were going to pause and rethink these measures. I’m particularly saddened that this really seems to be about the European referendum campaign rather than about DWP policy.

“From a personal perspective, for months I have been silenced by him and what I have said has been strictly controlled.”

Altmann said she had to accept that as a part of her role in government, but added that she was “horrified to see him abuse the freedom” given to him by the prime minister to take sides in the EU referendum.

“In particular, I was astonished that he attacked his own government for producing what he called ‘dodgy dossiers’ on the EU situation, which simply sought to set out the facts about this vital issue for our country’s future.” The final comment echoes a complaint made in recent days by senior figures in Downing street.

Her statement added: “I have found him exceptionally difficult to work for. It has been a hugely challenging time for me as he was preventing me from speaking to the public and has often been obstructive to my efforts to resolve important pension policy issues such as on women’s pensions.” She said she was looking forward to working with his successor, Stephen Crabb.

Altmann’s comments appeared to trigger a civil war inside his former department. The disability minister, Justin Tomlinson, hit back, saying: “Iain always conducted himself in a professional, dedicated and determined manner. He actively encouraged ministers and teams to engage, challenge and develop ideas. We were to be ourselves, our judgment backed as we worked as a team both for DWP and the government.”

Also in sharp contrast to Altmann, her DWP colleague Priti Patel, who is close to Duncan Smith and a fellow Eurosceptic, praised his record at the department.

“Since coming to office in 2010, he has made a real difference to the life chances of people throughout the country by reforming the welfare system to ensure that work always pays,” she said.

Duncan Smith received a text message from another minister in his department, Shailesh Vara, who also works on pensions. “I have to say I’m surprised by Ros’s comments,” she wrote.

“The fact is that I recall Ros attending all the meetings at which we openly discussed government policy and then we both went out to defend the policy in the Commons and Lords, which as you know wasn’t always easy to do. Ros’s recollection does not accord with mine and I’m sorry that this has all happened.”

Duncan Smith’s former aide, Philippa Stroud, pointed the finger of blame for the internal chaos at George Osborne, accusing the chancellor of “attritional” warfare over welfare cuts.

“Every budget, every spending review, the Treasury would set a target for welfare cuts and say jump to meet it – and every time there would be the mother of all battles to protect people, and Iain would see them off,” she wrote in an article for the Sunday Times.

“There was a real danger of boiling frog syndrome. Iain was always watching for when enough was enough. With the cuts to disability benefits, that moment had arrived.”