Rishi Sunak's promised new treaty with Rwanda looks unlikely to be ratified before the new year as he struggles to get flights under his grounded asylum policy in the air in the spring.
The deal the Prime Minister hopes to sign after the High Court defeat was only billed on Monday but is now not expected before Wednesday's Autumn Statement.
Mr Sunak has pinned his hopes on a new legally binding pact with Kigali along with emergency legislation after the High Court ruled the policy illegal on 15 November.
Downing Street had said in the hours after the defeat that the deal would be put before parliament in the “coming days” so that evacuation flights could take off “as soon as possible”.
But Whitehall sources said the treaty is not expected to be published until shortly after Chancellor Jeremy Hunt details his economic announcement on Wednesday.
With the Commons expected to rise for the Christmas break on December 19, there are not enough sitting days to ratify the treaty before the New Year under the current schedule, with No 10 saying at least 21 are needed.
Labour's shadow home secretary Yevette Cooper said: “This is just another mess from the Tories. Further delay in a plan that has already failed. “This is yet more hot air, rhetoric and mayhem from a Tory party that is clearly incapable of stopping criminal gangs or delivering on their promise of small boats.”
Downing Street said “further details will be provided in the coming days”, as a source sought to downplay any suggestion of a delay in signing the deal with Rwanda.
On Sunday, Mr Hunt threw his support behind Mr Sunak to solve the “terribly complex” challenge of making Rwanda's asylum policy work, as the pair set their sights on a first flight in the spring.
Sacked Home Secretary Suella Braverman has stepped up the pressure, arguing that “improving and perfecting” it will not succeed in pulling the flights before the election.
Mr Hunt admitted politics was “not an easy business” but said Mr Sunak was “the most persistent, most determined prime minister I have ever worked with”.
He suggested that Mr Sunak is more determined when it comes to solving problems than Lord David Cameron, the former prime minister who returned from the political wilderness to become foreign secretary in the reshuffle.
“I really enjoyed working with David Cameron, but when it comes to solving terrifyingly complex problems, I've never worked with anyone as amazing as Rishi,” Mr Hunt told the BBC's Laura Kuensberg on Sunday.
“I think we'll see, because I think when you interview me next year, we'll talk about how we achieved this plan and I'll say ‘look, it wasn't easy, I kept it, but this is what we promise to do.'
The source expected no problems getting Kigali to sign the treaty, believing emergency legislation to be the biggest challenge.
In an interview with the Mail on Sunday, Ms Braverman said the Prime Minister lacked the “moral leadership” to tackle the pro-Palestine marches, which she described as “mobs”.
He welcomed Mr Sunak's plans for emergency legislation but said the changes needed to be “meaningful”, adding that “tweaking and fine-tuning is not going to cut it… and we will not be withdrawing flights before the next general election ».
The Tory MP said elements of domestic and international human rights law should be excluded, as some colleagues on the right want the European Convention on Human Rights to be scrapped altogether.
However, Mr Hunt told the BBC that “at this stage” he did not believe it was necessary to follow Vladimir Putin's Russia in leaving the ECHR.
“What we are saying is ultimately … Parliament, the elected representatives in Parliament, not foreign judges, should decide who can come to this country,” he said.
“We don't think it will come to that at this stage, we think there are ways we can avoid it, we don't want to.”
Former High Court judge Lord Sumption has argued that the Rwanda plan is “probably dead” in its current form and believes judges at the European Court of Human Rights would likely agree with UK chief justices who blocked the plans.
“She will investigate the security for herself and probably come to a conclusion very similar to that of the High Court,” he told Sky's Sunday Morning with Trevor Phillips.
The five judges ruled on Wednesday that the policy was illegal, citing concerns that Rwanda could send genuine refugees back to the countries they fled.