The schedule would not look to renegotiate the deal, but “flesh out” what has already been agreed. It would attempt to assuage Brexiteers’ concerns by including specific examples of conditions that, if met, would allow the UK to leave the backstop. May was said to have responded positively to the suggestion.

One condition could include the development of the Brexiteers’ favoured “maximum facilitation” plan for a technological solution to the Irish border. At Tuesday’s cabinet meeting, ministers were told “alternative arrangements” such as max fac could present a way out of the backstop.

Downing Street hopes this, plus language in the political declaration on the future relationship, will provide a fig leaf that convinces Brexiteers a Canada-style free trade agreement is still on the table, giving them a political ladder to climb down to vote for May’s deal. An official close to one cabinet Brexiteer told BuzzFeed News there were “good vibes” from today’s meeting.

Under one proposal put forward by cabinet Brexiteers this week, the decision as to whether the conditions to leave the backstop had been met could be made on the recommendation of the North South Ministerial Council, the body established under the Good Friday Agreement made up of members of the Northern Irish and Irish executives.

The schedule, which as an annex to the withdrawal agreement would be legally binding, would prevent the EU or UK from “unreasonably” vetoing a North South Ministerial Council recommendation to end the backstop. It would, however, fall short of the unilateral break clause that Brexiteers had previously sought, and would still rely on mutual agreement with the Republic of Ireland.

An EU source suggested that provisions to take into account the decision-making terms of the Good Friday Agreement, such as consultation with the North South Ministerial Council, were already covered in the withdrawal agreement.