So what are their new red lines?

Any concession on the Irish backstop must include a ‘clearly-worded, legally-binding’ clause which ‘unambiguously overrides’ the Withdrawal Agreement.

The new tests demand the language in any concession ‘must go beyond simply re-emphasising/ re-interpreting the temporary nature of the backstop’ and lead to a change in Attorney General Geoffrey Cox’s advice that it could ‘endure indefinitely’.

Brexiteers also insist that the changes must demonstrate ‘a clear and unambiguous route out of the backstop if trade talks fail’.