Rishi Sunak has been warned that more than 100 Tory MPs could rebel over a deal with the EU to help break the post-Brexit deadlock in Northern Ireland, as Boris Johnson launched a major intervention calling for him to take a tougher line with Brussels.
Pressure is growing on the prime minister as government sources said tense talks in Downing Street over the weekend on overhauling the Northern Ireland protocol were yet to yield a breakthrough.
