The first flight taking asylum seekers to Rwanda will jet off tonight - even if there are dozens of empty seats, a senior Tory has said.
Foreign Secretary Liz Truss insisted the policy was "completely moral" amid a growing backlash over plans to ship migrants who arrive in the UK by illegal means to the east African country.
Church of England leaders, including the Archbishops of York and Canterbury, branded it an "immoral" plan that "shames Britain".
But Boris Johnson told the Cabinet he would not be "deterred or abashed" by criticism - and accused lawyers representing migrants of "abetting the work of criminal gangs".
Addressing his top team, he said: "The objective is to ensure that we make that clear distinction that I think everybody can see is fair and reasonable between legal immigration to this country by safe and legal routes... and distinguishing that from dangerous and illegal cross-Channel migration which we intend to stop".
Ms Truss vowed the first flight would go ahead tonight even if only a handful of asylum seekers were on board.
The plans are being kept tightly under wraps but the plane is reportedly expected to leave tonight at around 9.30pm - if the Government can defeat the latest legal challenges.
"We are expecting to send the flight later today," Ms Truss told Sky News.
"I can't say exactly how many people will be on the flight but the really important thing is we establish the principle and we start to break the business model of these appalling people traffickers who are trading in misery."
Last-ditch attempts to block the removal failed after three Court of Appeal judges upheld a High Court ruling that it could go ahead.
But as few as seven people could be on the plane, which is reportedly a 200-seat Boeing chartered by the Home Office at a cost of up to £500,000.
A Government source said the overall figure would be lower but added: "You can’t put a price on saving lives and defending our border."
Ministers had initially planned for up to 130 people to be on the initial flight but Care4Calais, one of the charities that brought the legal appeal, said that just seven migrants expecting to be removed still had live tickets.
Three further challenges are expected to be heard at the High Court today.
Ms Truss warned: "There will be people on the flight and if they are not on this flight they will be on the next flight."
She said she "can't put a figure" on the cost of the flight but said ministers must "reduce the cost over time of illegal immigration" as they battle to curb numbers of desperate people making the journey in small boats.
"It is value for money," she insisted to Sky.
Archbishop of Canterbury Justin Welby and Archbishop of York Stephen Cottrell said the policy "should shame us as a nation".
"This immoral policy shames Britain," they said in a letter to the Times also signed by the bishops of London, Durham, Exeter, Birmingham and Manchester.
But Ms Truss said the "people who are immoral in this case are the people traffickers trading in human misery".
"Those people need to suggest an alternative policy that will work," she said.
"Our policy is completely legal, it's completely moral."
Detention Action, the other charity involved in the appeal, said it was "disappointed" with the Tuesday's legal ruling but would continue to press ahead with a full legal challenge to the policy due to be heard next month.
"Throughout these injunction hearings, we have heard powerful evidence against this policy and we are confident that, when our full legal challenge is heard in the High Court in July, this Government will be forced to abandon this policy and bring back anyone who is ultimately removed," deputy director James Wilson said.
