Boris Johnson's keynote Brexit speech should not be taken seriously "given everything he said about that bus", a former Labour minister has said.
The Foreign Secretary is expected to insist that leaving the bloc is a cause for hope, not fear, as he sets out his vision for a post-Brexit Britain.
To make Brexit a success, supporters must "reach out to those who still have anxieties", he will urge.
Labour former minister Yvette Cooper dismissed his comments however and called on the Government to focus on detail rather than rhetoric.
Speaking to BBC Radio 4's Today programme, she said: "The problem with that is, from the point of view of a committee chair, we've got this speech being made which doesn't seem to set out any detail.
"The Government cannot keep kicking the can down the road, we've got to actually have some practical details on it.
"To be honest, given everything he said about that bus, I don't really see why we're taking him seriously at all."
Ahead of Mr Johnson's speech, Swedish ambassador to the UK Torbjorn Sohlstrom warned that red lines do not "marry with friction-free trade".
He said: "It's clear that if Britain will indeed leave both the customs union and the single market and perhaps take some distance from EU rules and regulations, there will be, I think, a degree of friction in the trade.
"There are strong incentives on each side to find a good arrangement and we will try to be as constructive as possible to achieve that sort of outcome, but I don't think it will be that easy.
"The British Government has set up a couple of red lines that is not so easy to marry with friction-free trade."
Senior Tory Daniel Hannan, who is an MEP and founding member of Vote Leave, said Mr Johnson's speech would be aimed at "reconciliation".
He added: "We want to try and carry as many people with us, it was a narrow outcome, it was a 48/52 vote that means we should try and find a consensus that both sides can at least live with."