LONDON—U.K. Treasury chief George Osborne said Monday that a British exit from the European Union could permanently damage its economy, as the government laid out its most detailed assessment yet of the potential economic implications of leaving the bloc.
Mr. Osborne, citing a new government analysis, said the U.K. economy could be around 6% smaller in 2030 if it left the EU than if it remains a member. That is a loss of income equivalent to £4,300 ($6,107) a year for every British household, Mr. Osborne said.
“Britain would be permanently poorer if it left the European Union. Under any alternative, we’d trade less, do less business and receive less investment,” Mr. Osborne said in a speech in Bristol, England.”British families will pay a heavy economic price if we leave the EU.”
Backers of a British exit dismissed the report. Conservative lawmaker Peter Bone called the predictions “speculative at best, deceitful at worst.”
The UK’s economic future is a key battleground in the country’s June 23 referendum on whether to leave the EU, with both sides in the heated campaign touting contrasting visions of the future of a U.K. less closely tied to Europe. Estimates of the economic impact of a British exit have varied wildly, largely because of uncertainty about how the U.K.’s eventual trade relationships would look.
British Prime Minister David Cameron, who is spearheading efforts to persuade Britons to vote to remain, has made economic security central to his arguments. President Barack Obama is likely to add his support for Britain’s continued membership during a visit this week.