Quitting the European Union would leave households £4,300 a year worse off, George Osborne warned as he prepared to release in-depth Treasury analysis on the cost of Brexit.
Britain's economy would shrink by 6% by 2030 if the country replicated Canada's trading agreements as advocated by Boris Johnson, according to the Chancellor.
The 200 page Government report assessing the long term costs and benefits of EU membership as well as life outside shows the country would be left "permanently poorer".
In an article for The Times, Mr Osborne said: "The conclusion is clear: for Britain's economy and for families, leaving the EU would be the most extraordinary self-inflicted wound."
The study will say none of the alternative options to full EU membership would leave Britain with a quota-free, no-tariff access to a single market of half a billion consumers.
Mr Osborne added: "The Treasury analysis shows that under all plausible alternatives to British membership of the EU we would have a less open and interconnected economy -- not just with Europe but, crucially, with the rest of the world.
"There would be less trade, less investment and less business. Leave the EU, and the facts are: Britain would be permanently poorer. Britain's families would be permanently poorer too."