Jo Swinson was the most warmly received of the party leaders to appear on stage at the CBI’s annual conference, as the Liberal Democrat leader’s unwavering commitment to remaining in the EU proved popular with business delegates.

As leaders did their best to promote their policies to the business community prior to the general election on 12 December, the audience’s reaction to both Boris Johnson and Jeremy Corbyn was lukewarm at best.

The prime minister’s promise that his “oven-ready” Brexit deal would end the uncertainty over Britain’s relationship with the EU found favour with many of the business leaders gathered, but there was also despair at the move toward extremes by both main political parties.

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Randle Slatter, the finance director of Clearsprings, a provider of accommodation to asylum seekers under contract from the Home Office, said he shared the view of the CBI director general, Carolyn Fairbairn, about the ideological shift to the extremes by both parties. He said the prospect of leaving the EU without a deal next December was his main worry. “We have to remain closely connected to the EU for trade. That is essential.”

Slatter said he was supporting the Liberal Democrats after having taken a long look at Labour. “Jeremy Corbyn is a decent man, it’s the people around him and the Momentum group that I find a problem,” he said.

Robert Moore, the marketing manager of insolvency group KSA, said he saw himself as on the centre right but not nearly rightwing enough to vote for a Johnson Tory administration. “I am more aligned with Michael Heseltine and people like that,” he said.

Moore, who will also be voting Lib Dem, said he wanted the next government to do more to end homelessness, build more affordable homes and reduce the need for food banks. With offices in London and Gateshead, he said he could see the gulf between different parts of the country, “which the next government should try to close”.

The director of an engineering company based in Scotland, who asked to remain anonymous, said she appreciated Corbyn’s “measured” speech but remained to be convinced by Labour’s plan to part-nationalise BT.

“It was more measured and calm than the prime minister’s [speech],” she said. “I liked the way Jeremy Corbyn answered questions directly; like, for example, the very strong way he answered questions on and dealt with antisemitism. But I am not sure that nationalising so much, including the fibre optic network is the way to go.”

Andrew Larkin, the manager of a fibre optic cable provider, said: “We know from experience that it will be be very ambitious to roll out fibre in the next 10 years.”

Larkin, who connects multiple-occupancy residential properties, student flats and government offices, said the success of his company could be tied to Labour’s nationalisation of BT’s Openreach business. “It is a huge task and you have to ask if they know what they are taking on.”

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Samantha Mickleburgh, the managing director of Duo Bootmakers, a company employing 35 people making women’s boots in Froome, Somerset, was more emphatic in her view of the Labour leader. “I don’t think he has a clue what he is taking about. He wants to nationalise things without any idea how it can be done,” she said.

Chris Buxton, the chief executive of the British Fluid Power Association (BFPA), which represents companies that make hydraulic and pneumatic equipment, told Swinson during a question and answer session after her speech that he was drawn to her policies, but the threat of a Corbyn government was driving him toward voting for the Conservative party.

“I’m scared to death of a Corbyn government,” he said. “I speak as a remainer when I say I would rather crash out of the EU without a deal than have Jeremy Corbyn in No 10.”