Downing Street has refused to recommit to Rishi Sunak’s spring deadline to get deportation flights off the ground to Rwanda, as his Bill remains stuck in deadlock after defiant peers again insisted on changes to the controversial scheme.

The Prime Minister’s spokesman said the timetable was initially set out in November “but obviously the Bill has continued to be delayed” by the House of Lords.

The proposed law aims to send some asylum seekers on a one-way trip to Rwanda in order to deter people from crossing the English Channel in small boats.

Mr Sunak has said he wants to see flights take off this spring but MPs will not consider the legislation again until Monday.

Pressed on whether spring was still the target, his spokesman told reporters: “Our intention is to get this passed on Monday such that we can then set out the timetable for getting flights off as soon as possible.

“I’m not going to get ahead of the Bill passing, which obviously we’ve seen again last night has continued to be held up.

“We’re working at pace to ensure these flights leave as soon as possible. It’s now incumbent on the Lords to pass this Bill such that we can trigger the final planning phases and ultimately stop the boats.”

Asked whether Mr Sunak should take some blame for the delay, his spokesman said: “No, I don’t accept that. The Bill was brought forward within weeks, rapidly following the conclusions of the Supreme Court.”

The Bill and a treaty with Rwanda are intended to prevent further legal challenges to the stalled asylum scheme after the Supreme Court ruled the plan was unlawful.

As well as compelling judges to regard the east African country as safe, it would give ministers the power to ignore emergency injunctions.

But the House of Lords on Wednesday snubbed ministerial calls to back down and again insisted on revisions to the Safety of Rwanda (Asylum and Immigration) Bill.

Despite MPs overturning previous changes by the upper chamber, peers renewed their demand that Rwanda cannot be treated as a safe country until an independent monitoring body has verified that protections contained in the treaty are implemented.

The provision would also allow the Secretary of State to effectively pull the plug on the scheme if the promised safeguards were not maintained.

In a further blow to the Government, peers again supported an exemption from removal for those who worked with the UK military or Government overseas, such as Afghan interpreters.

No 10 indicated the Government will not be making concessions on the changes demanded by peers.

The Prime Minister’s spokesman said the amendment on exempting Afghans who helped British troops “is unnecessary” as the UK already has “safe and legal routes” for them to come to Britain.

He said the change would “create an unnecessary and dangerous incentive for these people to travel here illegally, which is precisely what this Bill is trying to avoid”.

Earlier, Grant Shapps said ministers will do “whatever we need to do” to fly asylum seekers to Rwanda, in an apparent hint the RAF could be used for deportation flights.

It comes amid reports that RAF Voyager aircraft could be deployed after the Home Office failed to find an airline that would charter the flights.

Downing Street has drawn up plans to order the Ministry of Defence to repurpose at least one of the leased aircraft for this, according to The Times.

Defence Secretary Grant Shapps said the priority was to get the Rwanda Bill passed (Yui Mok/PA)

Defence Secretary Mr Shapps did not deny the suggestion, telling Sky News on Thursday: “We will do whatever we need to do to make sure that we can get these flights off, whether they are charter flights or other kinds of flights.”

He added that which aircraft took asylum seekers to Rwanda was a “secondary issue”.

The Home Office has also not denied the claim.

AirTanker, the company which supplies Voyager to the RAF, was paid a visit by campaigners from the charity Freedom from Torture on Thursday.

They stood at its gates with a banner urging it not to get involved, and claimed tens of thousands of people had written asking the same.

Sir Keir Starmer said the Rwanda scheme would not work regardless of how asylum seekers travelled to the east African country.

Asked whether he thought RAF aircraft should be used to deport asylum seekers, the Labour leader said: “I think the Government should be concentrating on how they are going to stop small boats from arriving in the first place rather than wasting time and money, taxpayers’ money, on a gimmick, however they travel to Rwanda.

“There are tens of thousands of people waiting to have their claims processed and the Government is talking about removing a few hundred.

“More people came in one day last week than this entire scheme will remove under its current provisions.”