The UK risks a decade of uncertainty if voters choose to leave the European Union in an in-out referendum in June, according to a government report released Monday, February 29, Bloomberg reports.

The UK’s trading arrangements with the EU are unlikely to be completed within the two-year negotiating process stipulated by the Treaty of the European Union, and its commerce with the wider world is also likely to be affected by a withdrawal, according to the report produced by the Cabinet Office.

“Uncertainty during the negotiating period could have an impact on financial markets, investment and the value of the pound, and as a consequence on the wider economy and jobs,” the report said. “A vote to leave the EU would be the start, not the end, of a process. It could lead to up to a decade or more of uncertainty.”

The government is stepping up its rhetoric in favor of staying in the EU as polls show a narrow advantage for the “remain” camp ahead of the June 23 vote. The British pound completed its worst week since the 2009 recession on Friday after a string of politicians including London Mayor Boris Johnson and Justice Secretary Michael Gove lined up for the “leave” side, opposing Prime Minister David Cameron.