Insisting being pro-Brexit and pro-business are "incompatible" in a charm offensive with leading industry figures, the Lib Dems said Conservative plans would leave British "businesses out in the cold"
It comes as the UK avoided a recession on Monday, with official figures showing the economy grew by 0.3 per cent in a sluggish third quarter of the year marred by Brexit uncertainty and a global slowdown.
On Tuesday, senior members of the Lib Dems' fundraising board met with prospective business donors in attempt to persuade them to fund the party's general election effort.
An internal party briefing provides "top lines" for those on the board to use with engaging with senior business individuals, urging them to highlight "just how bad Brexit has already been".
The party claims Mr Johnson's proposed Brexit deal would "make it much more difficult, complex and costly for British companies to sell" to the EU.
"You cannot be pro-Brexit and pro-business," one briefing line claims. "The two are incompatible."
Another adds: "Boris Johnson's Brexit plans would mean significant damaging barriers to trade and a major hit to our labour market. It will leave UK businesses out in the cold."
The party also urged its fundraising board to cite figures from the National Institute for Economic and Social Research (NIESR), who last month warned of a smaller economy through lost trade and lower migration.
In an email to the party's fundraising board, the party's director of donations added: "In advance of tomorrow's fundraising board meeting, please find attached a Brexit briefing to you for you to use in the conversations you are all having with prospective business donors.
"More and more business leaders are switching their support to us, and, in the wake of Farage crediting Boris's commitment to regulatory to divergence as central to his decision not to field Brexit candidates in Conservative seats."
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