"In the United Kingdom, the planned June referendum on European Union membership has already created uncertainty for investors; a "Brexit" could do severe regional and global damage by disrupting established trading relationships," Obstfeld said, according to prepared remarks.
He also stated that the possibility of the United Kingdom (UK) terminating its membership in the European Union (EU) bloc is real.
"One manifestation of increased nationalism is the very real possibility that the United Kingdom exits the European Union, damaging a wide range of trade and financial relationships," Obstfeld said.
UK citizens are set to vote on June 23 in a referendum on the country's EU membership, after Prime Minister David Cameron and the leaders of the 27 European Union member states reached a deal in February to grant the United Kingdom a special status within the bloc.
