The United Kingdom vowed on Wednesday to pursue its controversial policy to deport asylum-seekers to Rwanda after the first flight was canceled following a legal ruling, in an embarrassing blow to Prime Minister Boris Johnson's government.

The number of those due to be put on the flight on Tuesday had dwindled from an original 130 to seven and finally none after a last-minute order by the European Court of Human Rights (ECtHR).

British Home Secretary Priti Patel said she was disappointed that the "legal challenge and last-minute claims" meant the plane did not take off but insisted the heavily criticized program would go ahead.

"We will not be deterred," she said in a statement. "Our legal team are reviewing every decision made on this flight and preparation for the next flight begins now."

The grounding followed an ECtHR ruling that at least one of the asylum-seekers should stay in Britain as there were no guarantees for his legal future in Rwanda, an East African country thousands of miles away.

Patel called the ECtHR intervention "very surprising" and vowed that "many of those removed from this flight will be placed on the next."

Rwanda also said it remained committed to taking in the asylum-seekers under the April deal, which has come under fire from the United Nations, rights groups and church leaders.

"We are not deterred by these developments," Rwandan government spokesperson Yolande Makolo told Agence France-Presse (AFP). "Rwanda stands ready to receive the migrants when they do arrive and offer them safety and opportunity in our country."

The flight cancellation is an embarrassment for Johnson's Conservative government after Foreign Secretary Liz Truss insisted the Kigali-bound plane would leave no matter how many people were on board.

But the ECtHR issued an urgent interim measure to prevent the deportation of an Iraqi man booked on the flight as he may have been tortured and his asylum application was not completed.

The Strasbourg-based court said the expulsion should wait until British courts have taken a final decision on the legality of the policy, set for July.

Rights group Care4Calais tweeted that the same ECHR order could be applied to the others set to be transported to Rwanda. Truss has insisted the policy, which the United Nations High Commissioner for Refugees (UNHCR) has criticized as "all wrong," was vital to break up human-trafficking gangs exploiting vulnerable migrants.

'Shames Britain'

Legal challenges in recent days had failed to stop the deportation policy, which Church of England leaders described as "immoral" and said "shames Britain."

"We cannot offer asylum to everyone, but we must not outsource our ethical responsibilities, or discard international law – which protects the right to claim asylum," Archbishop of Canterbury Justin Welby and Archbishop of York Stephen Cottrell wrote in a letter to The Times.

It was reported last weekend that Queen Elizabeth II's heir, Prince Charles, had privately described the government's plan as "appalling."

But Truss said: "The people who are immoral in this case are the people traffickers trading on human misery."

Johnson has told his senior ministers the policy was "the right thing to do."

Truss said she could not put a figure on the cost of the charter flight, which has been estimated at upwards of 250,000 pounds ($303,000). But she insisted it was "value for money" to reduce the long-term cost of irregular migration, which the government says costs U.K. taxpayers 1.5 billion pounds a year, including 5 million pounds a day on accommodation.

Not 'a punishment'

In the French port of Calais, migrants said the risk of deportation to Rwanda would not stop them from trying to reach Britain.

Moussa, 21, from Sudan's Darfur region, said "getting papers" was the attraction. "That's why we want to go to England," he said.

Deported asylum-seekers who eventually make the 4,000-mile (6,500-kilometer) trip to Kigali will be put up in the Hope Hostel, which was built in 2014 to give refuge to orphans from the 1994 genocide of around 800,000 mainly ethnic Tutsis.

Hostel manager Ismael Bakina said up to 100 migrants can be accommodated at a rate of $65 per person a day and that "this is not a prison."

The government in Kigali, which is frequently accused of rights abuses, has rejected criticism that Rwanda is not a safe country.

"We don't think it is immoral to offer a home to people," spokesperson Makolo said Tuesday. "We do not consider living in Rwanda a punishment."