EU referendum: Iain Duncan Smith accuses David Cameron of having a 'low opinion of the British people'

Tory splits over the EU referendum are widening by the day

The Work and Pensions Secretary Iain Duncan Smith at Conservative party conference (PA)

Iain Duncan Smith has accused David Cameron and George Osborne of having a “low opinion of the British people” – further deepening the Tory split over the upcoming European Union referendum.

The Prime Minister warned on Saturday that leaving the EU would be a “great leap in the dark” while the Chancellor said on Friday that the policy would lead to a “profound economic shock”.

Directly referencing the Tory leadership’s claims, Mr Duncan Smith hit out at “pessimism” over Britain’s prospects and accused the In campaign of talking the UK’s capabilities down.

“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’?” the Work and Pensions Secretary told the BBC’s Andrew Marr Show.

“We talk about them not being capable, that we’re too small. I have a different view, that Britain is a great country, the people are inventive, innovative, and they will find a way to actually have a real deal.

“The In campaign’s whole strategy seems to be about basically saying we’re too small, we’re too little. I don’t know why anybody would want to run a country like this! This country is the greatest on earth.”

Mr Duncan Smith said he believed that upon leaving the EU Britain would be able to negotiate access to the European Single Market – but with the reintroduction of border controls to limit immigration.

Other non-EU countries with access to the single market have had to negotiate freedom of movement, and all – Iceland, Switzerland, and Norway – are members of the Schengen passport-free area – meaning they have weaker border controls than the UK.

“The trade deal is very simple: that we would want them to be able to access out market freely without special and extra tariffs, we would want to be able to access their marketplace,” he said.

“Part of our red lines will be about us being able to control the borders as we want. We’d want migration but we’d want it as controlled migration so we can cope with it. That deal is very doable.”

Mr Cameron has said that any idea further concessions could be extracted from the EU was “for the birds”.

Tempers have frayed in Tory ranks over the Europe issue in recent weeks, with Foreign Secretary Phillip Hammond reportedly having called a eurosceptic Conservative MP “a total s**t” after he defied orders to keep a report on the EU under wraps.

Last week Mr Cameron publicly ridiculed Boris Johnson’s decision to back the “out” campaign, hinting that he had done so in order to further his political career within the Conservative party.

The spat comes after Mr Duncan Smith said it was “wrong” for ministers loyal to Mr Cameron to anonymously brief that eurosceptics standing up to the party leadership should be sacked.

Mr Duncan Smith himself faced criticism and disbelief last week when he claimed EU membership made Britain more vulnerable to terrorist attack.

Mr Cameron bowed to pressure last year and said he would allow Cabinet ministers to campaign on either side of the EU referendum – an unusual move in light of Cabinet collective responsibility.

The European Union referendum will be held on 23 June. Polls are variable but averages appear to show a small lead for the remain campaign.