Britain's Treasury says house prices could fall by up to 18 percent if the country leaves the European Union — a claim dismissed as scaremongering by campaigners for a U.K. exit from the bloc.

Treasury chief George Osborne says leaving the EU would be a "profound economic shock."

Treasury analysis estimates property prices will be worth between 10 and 18 percent less by 2018 if Britain leaves than if it stays.

Osborne says Britain and its people "are going to be poorer outside the EU."

Energy minister Andrea Leadsom, who backs a "leave" vote in Britain's June 23 referendum, said Saturday that "the greatest threat to the economy is the perilous state of the euro" currency used by 19 EU states, and Britain should "take back control" of its finances.