Iain Duncan Smith accuses Cameron and Osborne of 'dividing' Britain in furious attack following resignation

Former Work and Pensions Secretary brands the Chancellor's budget, which included tax breaks for higher earners, 'deeply unfair'

Iain Duncan Smith has sparked a dramatic escalation of tensions in the Conservative Party with an astonishing attack on the Government’s record, warning that David Cameron and George Osborne risk “dividing society” with their cuts to welfare.

The former Work and Pensions Secretary, who resigned on Friday citing alarm at new £4.4bn cuts to disability benefits, told the BBC’s The Andrew Marr Show that the Government had to stop “bearing down” on working age benefit claimants to cut the deficit, branding the Chancellor's budget, which included tax breaks for higher earners, “deeply unfair”.

In his first interview since resigning, the former Conservative leader denied that his departure was the beginning of a coup against Mr Cameron and Mr Osborne, or that it was linked to the Cabinet split over the EU referendum.

But in condemning key pillars of the Government’s reform agenda, he delivered a serious blow to the authority of the Prime Minister and the Chancellor.

He described the welfare cap as “arbitrary” and accused Mr Osborne of pursuing “a desperate search for savings”, which he said had come at the expense of reforms that would help benefits claimants back into to work, and risked destroying the Conservative’s claim to be a “one nation party”.

“Yes we need to get the deficit down but we need to make sure we widen the scope of where we look to get that deficit down and not just narrow it down on working age benefits,” he said. “Otherwise it just looks like we see this as a pot of money, [and] that it doesn’t matter because they don’t vote for us.”

He said the Government was “in danger of drifting in a direction that divides society rather than unites it.”

“That I think is unfair. I’m not in the business of morality and everything else, I leave that to churchmen. I simply say that as far as I am concerned the risk is there.”

Mr Duncan Smith said resigning had been a “painful” decision, but had not been “about attacking the PM or Europe”.

He defended his own record as Work and Pensions Secretary, during a tenure in which he endorsed previous cuts to the welfare budget, as well as controversial policies such as the bedroom tax and the troubled transition to Universal Credit. He claimed he had worked hard “behind the scenes” to “even out and smooth out those policies.”

It has been reported that the Prime Minister branded his former Cabinet colleague “dishonourable” on hearing of his decision to resign, while extracts from a new book by former Lib Dem Coalition minister David Laws claim that Mr Cameron and Mr Osborne attempted to sack Mr Duncan Smith four years ago.

Responding to his latest salvo against the Government, Energy and Climate Change Secretary Amber Rudd said Mr Duncan Smith was “completely wrong” to say the Government was not pursuing one nation conservatism and said she resented his “high moral tone”.

“We are a team as a government, as a cabinet and he has broken ranks with that team and it’s upsetting,” she told Sky News’ Murnaghan programme.

But Mr Duncan Smith’s former colleague, pensions minister Baroness Ros Altmann told BBC Radio 5 Live’s Pienaar’s Politics she believed his resignation had been “all about Europe”.

“It’s been the impression I’ve had for some time that Europe was the thing that really mattered and the rest of it not so much,” she said. “I do think this definitely has to be about Europe. The timing of it and the way it’s happened when the policy that he had supported, we’d already agreed to revisit.”

She said Mr Duncan Smith had “silenced” her for months, preventing her from speaking to the media or tweeting about the Government’s pensions and welfare reforms.

“Iain has pushed through these measures, he has supported these measures…we’ve had discussions about it and he’s explained why the current system needed to change, it wasn’t working well. Therefore I am really surprised he has resigned in this way.

“I really do think this is all about Europe…the department has supported the cuts…As far as my experience is concerned it seems to be this is about Europe…it’s about the difficult relationship between certain personalities at the top of government,” she said.