Downing Street has insisted it did not put pressure on the British Chambers of Commerce (BCC) to suspend its leader over comments suggesting the country could have a “brighter” future outside the EU.
Number 10 said it was “surprised” by the views expressed by John Longworth, the BCC’s director general and acknowledged that it “regularly” speaks to business organisations.
But a spokesman stressed that “no pressure” was put on the BCC to suspend Mr Longworth.
Mr Johnson claimed the business leader had been crushed by the agents of Project Fear — the label used by Brexit campaigners to criticise the tactics used by David Cameron and his allies backing a Remain vote.
On BBC One’s The Andrew Marr Show, Mr Johnson hit out at the approach of the Remain camp.
“This is like the jailer has accidentally left the door of the jail open and people can see the sunlit land beyond,” he said.
“And everybody is suddenly wrangling about the terrors of the world outside. Actually it would be wonderful. It would be a huge weight lifted from British business.”
He added: “It is very sad that someone like John Longworth, who shares my view, who has great experience of British business and industry, should have paid quite a heavy price, it seems, for sharing that optimistic view.”
Mr Johnson said: “He had been asked to step down for expressing what I think is a passionate, optimistic view of this country’s chances.”
The London mayor, whose decision to back a Brexit came after uncertainty about his stance and his own political ambitions, insisted that he was “certainly not” expecting to be the next prime minister.
He insisted that Mr Cameron’s position would be secure even if the country voted to leave the EU on June 23.