LONDON    -    The leaders of Britain’s three biggest national political parties were making election pitches Monday to business leaders who are skeptical of politicians’ promises after years of economic uncertainty over Brexit.

Prime Minister Boris Johnson was also facing new questions about his relationship with an American businesswoman who allegedly received favors and public funds while Johnson was the mayor of London.

Britain’s stalled departure from the European Union is the overriding issue in campaigning for the U.K.’s Dec. 12 election, which is being held two years early because Johnson is seeking to get a majority of lawmakers to pass his Brexit divorce deal with the European Union. More than three years after the U.K. voted to leave the 28-nation bloc, the terms of the country’s departure and the nature of its future relationship with the EU remain unclear.

Conservative leader Johnson, Labour Party chief Jeremy Corbyn and Liberal Democrat leader Jo Swinson were all due to address a conference of employers’ group the Confederation of British Industry on Monday.

Johnson brought a promise to cut business taxes, while Corbyn was pledging a major apprenticeships program. Swinson was arguing that the centrist Liberal Democrats are the “natural party of business” because they want Britain to remain in the EU — a view shared by many industries.

Johnson, meanwhile, continued to be dogged by allegations that he gave special treatment to Jennifer Arcuri — a tech entrepreneur with whom he had a personal relationship — while he was mayor of London between 2008 and 2016.

Investigations have been launched in the wake of a Sunday Times report that Arcuri, 34, was given financial grants and privileged access to trade missions to the United States, Israel and Asia that Johnson led as mayor.

Johnson has insisted that “everything was done with full propriety.”

In a series of U.K. media interviews, Arcuri said she had a “very special” relationship with Johnson lasting several years. Johnson, now 55, was married at the time.

“It was not just a sexual intention,” Arcuri told the BBC. “He was very intrigued by my energy.”

She accused the prime minister of ignoring her when she tried to contact him about how to handle the media fallout from the allegations. Speaking to broadcaster ITV, Arcuri accused Johnson of casting her aside “like some gremlin.”

“I’ve kept your secrets, and I’ve been your friend,” she said. “And I don’t understand why you’ve blocked me and ignored me as if I was some fleeting one-night stand or some girl that you picked up at a bar because I wasn’t. And you know that.”