A cross-party group of British MEPs has called on the Government to stop the use of hostile terms like "war cabinet", "punishment" and "blackmail" when talking about Brexit.
In a letter to Foreign Secretary Boris Johnson, the 20 MEPs warn that the deployment of the language of "war and conflict" by ministers and media is harming Britain's hopes of friendly future relations with the remaining 27 EU nations.
They called on Mr Johnson to "unreservedly condemn" such phrases and ensure the Government leads by example by "de-escalating" its own rhetoric.
"Terms such as 'war cabinet', 'punishment', 'demands', 'blackmail' and similar do not promote an image of a deep and special relationship, but a hostile one," warned the MEPs.
"In the last week, utterly inappropriate terms such as 'weaponising', 'annexing' and 'provocation' have been widely used in relation to the draft exit treaty and its proposed protocol on the border between Ireland and Northern Ireland.
"Aside from the extremely questionable morality of the use of such terms, they also serve to damage the UK's future prospects greatly. Their use is self-defeating in every respect."
Use of "inflammatory language" is undermining efforts to build trust and limiting the room for manoeuvre for EU27 leaders with their own electorates when trying to fashion a co-operative future relationship with the UK, they said.
And they said the war-like terms risk damaging the UK's reputation around the world: "The mantra of Global Britain rings hollow when it is accompanied by needlessly aggressive language directed at our closest partners."
Liberal Democrat MEP Catherine Bearder said: "'War cabinet' and 'Annexing' is polarising, hostile language and goes down really badly with EU governments. With 19 other MEPs cross-party I have written to Boris Johnson asking for this to change."