U.K.’s Budgets Will Suffer From an EU Exit, Study Says

LONDON—A British vote in favor of leaving the European Union could thwart U.K. Treasury chief George Osborne’s goal of closing the nation’s budget deficit by 2020, according to an analysis by a nonpartisan think tank.

The Institute for Fiscal Studies said it found that a vote to leave the EU in a referendum next month would likely slow the economy, lowering tax receipts and pushing up government spending over the next few years,...