OTTAWA - Finance Minister Bill Morneau is warning Britain that tens of thousands of jobs at Canadian firms in the United Kingdom are vulnerable because of the debate around the country's potential exit from the European Union.

Speaking to reporters in London, Morneau says Canadian companies with investments in the U.K. are anxious about the uncertainty caused by the so-called Brexit vote later this month.

He says Canadian businesses that invested in the U.K. to access the European market may be forced to rethink their strategies.

Morneau says Ottawa believes the U.K. is stronger as part of a united Europe -- which he adds is also better for the Canadian economy and the still-to-be-signed Canada-EU free trade deal.

He says he hopes Britons will consider this as they make their decision in what is expected to be a close referendum.

Last month, Prime Minister Justin Trudeau suggested in an interview with Reuters news agency that it would be difficult for Britain to replicate its own version of the Canada-EU free trade deal, known as CETA.