He must fend off a potential rebellion from both the moderate and more extreme factions of his party, as up to 200 MPs prepare for a crucial debate on Monday.

To prevent defeat in Tuesday's parliamentary vote, Sunak requires fewer than 56 abstentions or 28 opposing votes. Allies of Sunak have been working throughout the weekend to convince members from both wings of the party to support the bill, which aims to limit legal challenges against migrant deportations to Rwanda.

A government insider suggests Sunak may be considering concessions but believes the bill is strong enough to ensure deportations move forward.

In the midst of this, Sunak will testify at the Covid inquiry about the "eat out to help out" program, which has faced criticism for its role in the 2020 virus spread. Concurrently, right-wing Conservatives, including former immigration minister Robert Jenrick who opposes the bill, will meet to discuss potential opposition and amendments.

Later, the centrist One Nation Conservatives will convene to decide their stance, with the possibility of supporting the bill's initial reading but resisting amendments that would bypass international human rights standards.

As Sunak grapples with his leadership and the contentious bill, there is increasing chatter about a potential challenge to his position, with some within his party contemplating reinstating Boris Johnson or an ally of Liz Truss.

Despite the turmoil, prominent Conservatives such as Michael Gove defend the bill's legality and downplay the prospect of an early general election, regardless of the vote's outcome.