Home Secretary James Cleverly returned from Kigali earlier this week after ironing out issues in the original plan.

However, the Prime Minister was dealt an almost instant blow after Robert Jenrick resigned as Immigration Minister amid concerns the Bill does not go far enough.

WATCH NOW: Home Secretary James Cleverly updates MPs on the Rwanda plan

Critics, including ex-Home Secretary Suella Braverman, warn Sunak’s current plan could even risk “electoral oblivion” for the Tory Party.

But the Prime Minister’s allies warn going further could put the entire scheme at risk.

A No10 source told GB News: “The choice is clear: our Bill, which is the toughest ever put to parliament and cannot go any further, or Labour, who have no plan at all.

“MPs need to come together so we can finally stop the boats, which are already down by a third under this Prime Minister.”

Shipley MP Phillip Davies echoed concerns about “self-indulgent” rebels enabling Labour to enact its own policy to curb illegal Channel crossings.

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He said: “There’s no excuse for Conservative MPs not to support what Sunak is doing.

“They should get behind it and turn their guns on Labour.

“It’s a Labour Government that’s the real threat to the country, not a Conservative Government.”

The Prime Minister’s allies were keen to claim Labour does not have a plan to tackle illegal immigration.

Sir Keir Starmer previously put forward measures to negotiate a returns agreement with EU countries, recruit 1,000 new caseworkers to clear the asylum backlog, set up temporary Nightingale Asylum Courts to speed up the decision-making process and fast-track decisions on applications from “safe” countries.

Conservatives have argued Labour’s plan would result in 100,000 migrants entering the UK every year.

However, Labour has rejected this suggestion and vowed not to join the EU quota scheme.

Despite calls to back Sunak, it is yet to be seen if concern about Labour will be enough to keep Tory rebels in line.

GB News understands that a meeting between the ERG, New Conservatives and Common Sense Group was focused on MPs being united on what No10 needs to deliver.

Responding to calls to back the Prime Minister on Tuesday, a source close to the European Research Group paraphrased Mandy Rice-Davies’ oft-quoted Profumo scandal comment.

The insider told GB News: “Using that famous phrase, ‘Well they would say that, wouldn’t they?’”

A Tory MP also seemed to suggest Sunak’s position remains precarious.

They said: “At the moment he’s not persuading either wing of his party and there’s a pretty strong chance there will be a leadership challenge before the next election.”

Despite telling Conservative MPs to “unite or die”, the Prime Minister stopped short of making Tuesday’s division a confidence vote.

Sunak made the Rwanda policy a cornerstone of his commitment to stop boats crossing the Channel after entering Downing Street last October.

However, the legislation has been repeatedly delayed by legal challenges and no asylum seekers have been sent to Rwanda from the UK yet.

The Tory right want the Bill to go even further by preventing the possibility of legal challenges under domestic and international human rights laws.

During his press conference on Thursday, the Prime Minister warned the Bill was already pushed to its limits.

He said: “Going any further would mean that Rwanda would collapse the scheme and then we’ll have nowhere to send anyone to – and that is not the way to get this going.”

Sunak added: “The question is for everyone else, and crucially the Labour Party, what’s their plan? They are going to vote for this legislation?”

But Shadow Home Secretary Yvette Cooper voiced her dismay at the sheer cost of the scheme, describing the £240million spent so far as “incredible”.

She added: “How many more blank cheques will Rishi Sunak write before the Tories come clean about this scheme being a total farce?

“Britain simply can’t afford more of this costly chaos from the Conservatives.”