Boris Johnson is to attempt to reassure voters who are angry and alienated by Brexit that the UK’s split from the EU is a cause for “hope not fear”.
The foreign secretary will use a speech to try to build bridges with those who voted to remain in the EU, saying their belief in European solidarity is based on “noble sentiments”.
“It is not good enough to say ‘you lost, get over it’,” he will say.
But he will also insist those who want to stop Brexit cannot prevail.
In the speech in London, he will say that that holding another referendum on the UK’s membership of the EU would be a “disastrous mistake that would lead to permanent and ineradicable feelings of betrayal”.
Labour MP Chuka Umunna, who supports the Open Britain campaign “against a hard, destructive Brexit”, said Mr Johnson was “totally unqualified to preach about the perils of fear and betrayal”, having “engaged in disgraceful scaremongering” during the EU referendum.
Mr Johnson’s speech is the first in a series of speeches by Theresa May and her ministers on the “road to Brexit”.
The prime minister is expected to address the UK’s future relations with the EU in a speech in Munich on Saturday, the day after she holds talks with German Chancellor Angela Merkel in Berlin.
In what has been billed as his most substantial speech on Brexit for more than a year, Mr Johnson – a leading figure in the Leave campaign during the 2016 referendum – is expected to make the “liberal case” for the UK’s withdrawal and argue it will allow the country to play a greater role on the world stage.
Excerpts released in advance of the speech suggest Mr Johnson will appeal to both sides to move on from the divisions of the past and unite around a shared goal of seeing an outward-facing and global nation succeed.
“We must accept that many [Remainers] are actuated by entirely noble sentiments, a real sense of solidarity with our European neighbours and a desire for the UK to succeed,” he will say.
“If we are to carry this project through to national success – as we must – then we must also reach out to those who still have anxieties.
“I want to try to anatomise at least some of those fears and to show to the best of my ability that they are unfounded and that the very opposite is usually true: that Brexit is not grounds for fear but hope.”