Rishi Sunak 'told Rwanda flight law will make it EASIER for migrants to stay in Britain' as Tory 'five families' go to war for soul of party amid 'insane' threats to replace PM as leader- as cost of project doubles to almost £300million

Rishi Sunak was warned that his new Rwanda flights law provided Channel migrants with 'easy' ways to avoid deportation, it was claimed today as the Tory civil war over the scheme deepened.

Two senior lawyers told the PM that the hastily drawn-up plan still gave arrivals the ability to individually challenge their removal to Africa in the courts. 

It came as the Home Office revealed that the cost of the agreement with Kigali has will rise from the initial £140million to £290million by 2025, despite no migrants having yet left the UK.

Mr Sunak is facing anger from the right and centre of the Conservatives over the new scheme, which is due to face its first vote in the Commons next Tuesday as he seeks to prevent a repeat of the previous iteration's Supreme Court defeat.

Groups dubbed the 'five families' feel that it is either too tough or not tough enough and are threatening not to support it.

And despite Tory chairman Rick Holden yesterday warning that replacing Mr Sunak before the general election would be 'insanity', there are reports that some backbenchers want him gone. 

Former Brexit minister Lord Frost issued what has been seen as a coded message in the Telegraph today, telling rebels that if they feel the 'current path' doesn't lead to a win 'they shouldn't be resigning themselves to it – they should be doing something about it'.

Legal migration minister Tom Pursglove began No10's attempt to salvage the vote today as he suggested rebels would get an opportunity further down the line to amend it before it becomes law if they back it in the initial second reading vote next week.

He told Sky the Tories had 'unity of purpose' over the bill and insisted the party would win the election under Mr Sunak. 

He also tried to play down suggestions that allowing migrants to challenge their individual removal to Rwanda could prove fatal to the plan.

He told Sky News: 'The legislation closes off so many of the grounds that people have come forward with in raising claims about being sent to Rwanda previously

'We believe that this is robust ... I believe that this will do the job.'

In a letter published late last night the Home Office confirmed ministers had signed off payments totalling a further £100million to Rwanda this year on top of the original £140million cost. A further £50million for next year has already been agreed, taking the total to £290million since the deal was first signed last year.

It insisted they were not linked to the signing of a new treaty with Rwanda this week. 

Millions more are expected to be paid if the Government eventually succeeds in deporting any Channel migrants there.

The emergence of the staggering figures is an embarrassment for the Home Office, which told MPs last month it would not provide a 'running commentary' on the cost.

Mr Pursglove defended the cost - mocked by Labour's Yvette Cooper as '£100million for every Home Secretary who has travelled to Rwanda for a photo opportunity'.

 He told Times Radio: 'Part of that money is helpful in making sure that we can respond to the issues properly that the Supreme Court raised, making sure that the capacity is in place to administer the partnership at the first possible opportunity.

'And I think it's right that we go about this in the way that we are and when you consider that we're spending £8 million a day currently in the asylum system you have to look at those spends in that context. That is not sustainable.'

The original £140million bill comprised £120million for the 'economic development and growth of Rwanda', with £20million to support 'initial set-up costs' for the scheme, including the creation of a reception centre in the capital Kigali in 2022.

But a planned deportation flight in June that year was blocked after a last-minute injunction by the European Court of Human Rights. 

This triggered a wave of legal action which eventually led to the scheme being ruled unlawful by the Supreme Court last month. 

Despite this, ministers signed off a further £100million payment in April this year for 'economic transformation' in Rwanda. 

The Home Office confirmed that a further £50million has already been agreed for next year.

If migrants are eventually sent to Rwanda, the UK Government has agreed to pay an additional per-person fee to cover living and administration costs.

Ministers had tried to keep the costs secret in the hope that they would not be revealed until flights have finally started. 

At an appearance before the Commons Home Affairs Committee last month, Home Office permanent secretary Matthew Rycroft said figures would only be released in an annual report next summer. 'Ministers have decided the way to update Parliament is annually, rather than by giving a running commentary,' he said.

Dame Diana Johnson, Labour chairman of the committee, said secrecy over the policy 'shows a total disregard for the vital role select committees play in holding the government to account'.

In his letter last night, sent after the Mail approached the Home Office, Mr Rycroft said 'ministers have agreed that I can disclose now the payments so far'. 

He denied reports the UK paid Rwanda a further £15million for signing the new treaty, adding: 'The Government of Rwanda did not ask for any payment in order for a treaty to be signed, nor was any offered.'