President Paul Kagame has offered to pay Britain back if the Rwanda migrant deportation deal falls through.
The Home Office has paid the Rwandan Government some £240million despite being engulfed in Parliamentary and legal battles to get the first flight off the ground.
Asked if the scheme was working, the President of Rwanda said: "Ask the UK. It's the UK's problem, not Rwanda's problem.
"The money is going to be used on those people who will come. If they don't come, we can return the money."
The offer of a refund is a fresh headache for Prime Minister Rishi Sunak as attempts to guide his Rwanda Bill through Parliament.
Conservative rebels, who are urging Mr Sunak to toughen up his Rwanda Bill, immediately seized on President Kagame's warning over repeated delays.
A Tory rebel source said: "As Michael Tomlinson explained this morning, the Government's plan is going to need hundreds of judges to clear thousands of claims which will take months and months at a bare minimum.
"Rwanda want a plan that works quickly, not one that satisfies the whims of our Attorney General.
"The government should therefore back our plan. At this rate it will be Labour having to pay back the money."
Rwanda could walk away from its multi-million pound deal with the UK and keep the money "without accepting a single asylum seeker", MPs heard last month.
Home Office permanent secretary, Sir Matthew Rycroft, told the Public Accounts Committee (PAC) there was a "break clause" included in the memorandum of understanding the UK and Rwanda signed in April 2022 to seal the deal, which allows either government to walk away from it with three months' notice.
He confirmed that if the UK instigates the break clause, Rwanda keeps the money already paid but added: "There is a presumption that the UK Government will want to continue with the partnership, bearing in mind its importance in the overall efforts to stop the boats."
If Rwanda ends the agreement, Sir Matthew said the country's government would have to repay the money "proportionately".
Under the Government's proposals, illegal migrants who cross the Channel on small boats could be flown out to Rwanda to have any asylum claims processed there rather than being allowed to apply to settle in the UK while they are still on British soil.
The legislation, plus a treaty signed with Rwanda's leaders in its capital Kigali, is intended to make the measures legally watertight following a court ruling blocking deporations.
But Tory rebels are concerned migrants could still lodge individual appeals against deportation orders.
And they are concerned European judges will still be able to ground flights to Kigali.
Former immigration minister Robert Jenrick urged MPs to "find a way through" the "entirely foreseeable" prospect of European judges challenging the Rwanda plan.
He told the Commons during Wednesday's debate: "What we're discussing here is whether or not we believe it is appropriate for a foreign judge in an international court to impose a late night judgment, often without the United Kingdom being able to give its own arguments or to hear the reasons for that judgment, whether we think that really accords with the rule of law.
"And, in particular in relation to this policy, whether we're willing to see the same thing happen again that did in the summer of 2022 whereby a judge did just that, grounded the flight, prevented the policy, led to months, indeed years of legal action and tens of thousands of illegal migrants breaking into our country, costing our taxpayers billions of pounds, imperilling lives in the Channel and perpetuating this challenge for years to come."
Mr Jenrick added: "I think as night follows day if we don't make changes in this respect, we'll find ourselves in a few months' time in exactly the same position that (Priti Patel) as home secretary was in the summer of 2022, whereby the Strasbourg court will issue one, potentially many rule 39 interim measures, the decision will fall to a minister ... about what to do, the courts will be involved and we'll find ourselves in a very difficult, indeed intractable situation.
"It is, as I've said before, a bit like pulling the pin out of a grenade but not being prepared to throw it. Setting this scheme in train without knowing what you would do when this happens - it's entirely foreseeable, let's find a way through this challenge."
Mr Jenrick told the Government he was "here to help" with his amendment aimed at safeguarding against Rule 39 orders.
The Tory former immigration minister told MPs: "We have the power to fix this and we have the responsibility. So let's use the opportunity we have today with the amendment that we have brought forward to resolve this.
"Or else we will be here in two months' time, the Strasbourg court will impose a Rule 39, the Government will be scrambling around how to resolve this, and the Government will have no-one else to blame.
"I am here to help the Government to ensure this policy works, because I like everyone, at least on this side of the House, believes passionately that we have to make this policy work and to stop the boats.
"So I strongly encourage the Prime Minister to support the amendment in my name, and that of many others, and encourage everyone else on all sides of this House who share my determination to fix this problem to do exactly the same." By Michael Knowles, Daily Express
