The IMF delayed publication of the report by a day after campaigning in the referendum was halted following the fatal shooting of Labour Party lawmaker Jo Cox on Thursday. Speaking on Friday, Managing Director Christine Lagarde said her thoughts were with Coxs family and friends.
In its report, the IMF presented forecasts for limited and adverse Brexit scenarios. In the worse situation, it sees growth slowing sharply this year and the economy shrinking 0.8 percent in 2017. The impact would see the economy 5.6 percent smaller by 2019 compared with a baseline forecast, while unemployment would rise above 6 percent and the deficit would be wider.
IMF officials said that a permanent hit to output would probably mean deeper austerity. Chancellor of the Exchequer George Osborne has said an emergency budget would be required within two months of a Brexit to fill a hole in the public finances.
While recognizing that this choice is for UK voters to make and that their decisions will reflect both economic and non-economic factors, directors agreed that the net economic effects of leaving the EU would likely be negative and substantial, the organization said.