British Prime Minister Theresa May | Matt Cardy/Getty Images Theresa May heads to Canada to seek trade deal British prime minister set to hold talks on ‘cementing a strong trade’ partnership with Canada post Brexit.

LONDON — British Prime Minister Theresa May will cross the Atlantic in pursuit of a post-Brexit trade deal on Monday.

A new working group to "swiftly transition" Canada's new trade deal with the EU into a deal with the U.K. after Brexit will be agreed when May meets her Canadian counterpart in Ottawa.

In a briefing note to journalists ahead of a three-day visit to Canada and the U.S., the U.K. government said May will hold talks with Canadian Prime Minister Justin Trudeau on "cementing a strong trade and investment partnership."

The two leaders are expected to agree that the EU-Canada Comprehensive Economic and Trade Agreement (CETA) has "significant potential to boost transatlantic prosperity — and should be swiftly transitioned to form a new bilateral arrangement between the U.K. and Canada after Brexit." CETA, which eliminates 98 percent of Canadian import duties, will be provisionally applied in the EU from September 21.

The U.K. is asking every country with which it currently has a trade deal as a member of the EU to adopt the same terms as it transitions out of the bloc after March 2019, May revealed during a visit to Japan in August.

The new U.K.- Canadian working group will be the 13th established to tackle post-Brexit trade deals since Britain voted to leave the European Union in June 2016.

In statements released ahead of the visit, which will also see May address the U.N. General Assembly in New York on Wednesday, May said the U.K. and Canada had a "long shared history."

“My visit to Canada today is not only about recognizing our past but also looking ahead to our bright future. We are both countries with ambitions to lead on the world stage and progressive values that underpin those ambitions — values including the importance of free trade, and respect for international law.

"When we come together and work as one to project our shared values on the world stage, we form a powerful union,” she said.

The two leaders are also expected to agree that Canada is a "natural partner" for the U.K. in "strengthening and improving" the World Trade Organization, which sets rules of trade between nations, according to the pre-released material.

But Liberal Democrat Brexit spokesperson Tom Brake accused May of "racking up air miles desperately trying to recreate what we have already."

"This copy-and-paste Brexit is a huge waste of time and resources," he said.

Labour MP Chris Leslie, a leading supporter of soft-Brexit campaign group Open Britain, said the best May could hope for was to "copy and paste" the deals the EU has negotiated on Britain's behalf.

“To preserve our trade, both with Europe and with economies around the world like Canada, Theresa May needs to rethink her ideological choice to leave the single market and the customs union,” he said.

The U.K. government also announced former junior Local Government Minister and Tory MP Andrew Percy would become the U.K.'s Canadian trade envoy.

The U.K. is the second biggest destination for Canadian investment abroad, after the U.S., and the bilateral trade relationship is worth £15.2 billion to both economies each year, according to the U.K. government briefing note.

May will also host a roundtable with Canadian businesses on Monday, with a raft of commercial deals announced to coincide with the visit. These include the expansion of Vancouver-based social media company Hootsuite in London, the expansion of Tesco’s product range to 100 west coast supermarkets by the end of this year, and a £34 million contract with construction and project management company Turner & Townsend to oversee refurbishment of part of the Canadian parliament.

May will travel to New York to the U.N. General Assembly from Canada where she is expected to focus on international efforts to fight modern slavery and online radicalization. She will also renew international support for the U.N.-backed political process in Libya.

She will also attend a meeting with tech companies including Google, Facebook and Microsoft to take stock of how extremist online content is being tackled.