George Osborne has been accused of implementing a "new policy on mass migration" by a Conservative MP as the Chancellor's Tory colleagues lined up to savage his pro-European Union argument.
Yesterday the Osborne published a Treasury analysis that argued every household in the country would be £4,300 a year worse off than if the UK remained in the EU.
Pro-Brexit Tories immediately rubbished the sums as "utter crap", while some seized on a line buried in the 200-page document that suggested that migration will add three million to the population - an admission seized on by right-leaning newspapers on their front pages.
Officials admit that the calculations on the negative impact of "Brexit", the equivalent of putting 8p on income tax, were based on immigration continuing to run at 185,000 every year, which would break the Tory promise to reduce immigration by tens of thousands.
Leave campaigners argue that Britain can only regain control its borders by quitting the EU.
Speaking in the Commons, Tory MP Stewart Jackson said: “I remember the good old days when the Chancellor regarded Treasury predictions as so discredited he set up the Office for Budget Responsibility instead. I can’t think what would have changed.
“The GDP projections in his dodgy dossier are predicated on breaking our manifesto commitment on immigration. The cost implications of his new policy on mass migration in areas like school places, housing, health and transport are not explicit in the document. Why is that?”
Sir Edward Leigh told Osborne that given "the Treasury can’t even get its forecast on growth and the deficit correct for next year" the EU analysis was useless.
"Doesn’t the Chancellor realise instructing his officials to produce a report, a speculative report, based on thoroughly tendentious figures about what might, or might not, happen in event of Brexit simply belittles the reputation of the Treasury for economic competence and forecasting.
Leigh added: "Instead of relying on fear why doesn’t he give us his vision compared to our vision of a free people in a free parliament controlling our own borders and leading the world towards free trade?"
Another Conservative, Sir Gerald Howarth, said: “I do hope he is not foolish enough to think those of us who wish to leave the EU want to retreat from the world, because the truth is far from that.
“We want the UK to break free from the sclerotic shackles of the EU and its super-state and embrace the exciting world out there which befits the world’s fifth largest economy, a nuclear power and a permanent member of the UN security council.”
And Philip Hollobone said the "disgracefully dodgy document" published by the Treasury was "worthy of the children's programme Jackanory".
Osborne defended the Treasury report. He told his eurosceptic backbenchers to produce "their own analysis" if they were so critical of his.
"Our positive vision is by being part of a reformed EU," he said. "We can raise living standards, create more jobs make sure consumers have access to lower process."