A senior treasurer within Britain's ruling Conservative party said Wednesday that a Donald Trump Presidency could boost inward investment into the U.K. and potentially ignite M&A activity.

"The biggest purchaser of U.K. business is the United States," Howard Leigh, senior partner of U.K. investment banking boutique Cavendish Corporate Finance LLP told The Street. A Donald Trump Presidency "might well propel U.S. companies to diversify out of America and buy more here. This could be helpful to U.K. M&A."

Leigh said he had attended the Republican Convention in Cleveland OH as an observer earlier this year and was assured that Trump would make a trade agreement with the United Kingdom a priority.

"I can only hope he's as good as his word," Leigh said.

Cavendish specializes in advising on the sale of mid-market U.K. companies. It only acts for the sell-side and sees the possibility of greater U.S. interest in British companies as a benefit.

Leigh, a vocal campaigner for Brexit, who is a member of Britain's upper house of Parliament, the House of Lords, conceded that Trump has in general been against free trade. But he believed that the president elect will be likely to make an exception for the U.K.

He said the Transatlantic Trade and Investment Partnership  (TTIP), a trade deal under negotiation between the U.S and the European Union, could provide a ready framework for an agreement between the U.S. and the U.K.

Negotiations on a TTIP have stalled and Leigh conceded that Trump would be unlikely to agree a deal with the whole EU. But he said if you took out the EU "and anything to do with it," then "of all the countries in Europe," Britain would be most likely to benefit.

However, Leigh also cautioned that there was a big uncertainty about the kind of people Trump will surround himself with and the kind of economic and foreign affairs advice they will give him.

"We just don't know who his advisers will be," he said. "With Clinton, the people were well-known. But not with Trump. That's going to be very important."

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