Leaving the EU would be the worst of all worlds, George Osborne will say today.

The Chancellor will warn that the UK would still have to accept high migration levels and contribute to the EU budget to be able to trade in the single market.

At the British Chambers of Commerce annual conference in London, where he will appear alongside German finance minister Wolfgang Schauble, he is expected to say: “We would be paying in to the EU, following their rules but have no say over those rules or how our money was spent."

"In other words, it would be the worst of all worlds.”

Last night the Foreign Secretary Philip Hammond accused some opponents of the EU of being prepared to "sacrifice" British jobs in order to cut ties with Brussels.

Out campaigners had put forward no "credible alternative" to membership, he said, and "working people would pay the price" with fewer jobs and rising prices.

he also warned that the status of Britons living in Spain and other EU countries could be thrown into doubt.

But his cabinet colleague Iain Duncan Smith accused the government of producing a “dodgy dossier” that suggested the price of a weekly shop would rise if the UK was outside the EU.

The phrase has echoes of claims around the report on Iraq that dogged Tony Blair’s government.

Mr Hammond hit backed saying he was "not surprised" by the Work and Pensions Secretary’s comments.

The paper looks at deals stuck between the EU and Norway and Switzerland as well as the option of going through the World Trade Organisation (WTO).

But, it says, none are as good as David Cameron’s renegotiation of the UK’s relationship with Brussels.

Mr Duncan Smith said the "real uncertainty" lay with the EU "project".

"As each day passes we see yet another example - from the utter failure to cope with the migrant crisis, to the increasing disaster of the euro," he said.

"This dodgy dossier won't fool anyone, and is proof that Remain are in denial about the risks of remaining in a crisis-ridden EU.

"The truth is we won't copy any other country's deal. We will have a settlement on our own terms - and one that will return control of our borders, and money to Britain. That's the safer choice."

Meanwhile, Erna Solberg, the Prime Minister of Norway, told the BBC: "For the UK to think that it will get everything it wants from the EU, without giving anything back... well, that just doesn't happen in a political organisation.

"We lack influence in important decision-making processes in the EU. We have special arrangements on some issues, but basically we have lost our sovereignty."

As the civil war within the Tories intensified a a senior Conservative MP also branded an In campaign slogan "blatantly misleading".

Commons Treasury Committee chairman Andrew Tyrie savaged Lord Rose, the chairman of Britain Stronger in Europe, over what he said was a "scandalous abuse of data".

Mr Tyrie urged the former Marks & Spencer executive chairman to retract the claim that EU membership is worth £3,000 to every UK household.

Matthew Elliott, chief executive of Vote Leave, accused ministers of scaremongering.

He said: "The Government is doing everything it can to falsely engineer a climate of fear about leaving the EU with ludicrous claim after ludicrous claim.

"The stream of taxpayer-funded propaganda is disappointing, disingenuous and unbecoming of the senior politicians sent out to defend it. It is undermining the open and honest debate the public want to have. The safe option is to vote Leave."

He added: "As the Foreign Secretary himself admitted this morning, of course we would be able to negotiate a free trade deal with the EU after we vote Leave."

A senior Downing Street source said: "The onus really now is on the Leave campaigners to give some honest answers to very reasonable questions.”