Boris Johnson has again defended the Government’s controversial immigration policy ahead of legal challenges – and reported concern from the Prince of Wales – over its plans to send some asylum seekers to Rwanda as early as Tuesday.

The Prime Minister said the Government had anticipated “a lot of teething problems” with the policy, but said the move is necessary to stop illegal people-smuggling rackets on either side of the Channel.

The Public and Commercial Services union (PCS), which represents more than 80% of Border Force staff, and charities Care4Calais and Detention Action will challenge in the Court of Appeal on Monday the High Court’s ruling on Friday that the first flight to the east African country can go ahead.

A second case is due to be heard in the High Court after Asylum Aid, a refugee charity, applied for an urgent interim injunction to stop the Government flying migrants to Rwanda.

It came as Care4Calais said on Monday morning that 11 of 31 migrants in a UK detention facility originally notified by the Home Office that they would be on the maiden Rwanda flight have since had their tickets cancelled.

The Prime Minister told broadcasters during a visit to a farm in Cornwall: “I always said that it will begin with a lot of teething problems and you will have a lot of legal action against it and they will try and delay it – that’s inevitable.

“But what we’re trying to do is stop the business model of criminal gangs who are preying on people moving them across the Channel in unseaworthy vessels, risking their lives and sometimes costing their lives.”

It came as Rwandan high commissioner Johnston Busingye told The Telegraph that his country will be a “safe haven” for migrants, after The Times and the Daily Mail reported that the Prince of Wales allegedly said in private that the policy is “appalling”.

Mr Busingye, writing in the paper, said “the Rwanda of today is unrecognisable from the country the world was introduced to” during the Rwandan genocide in 1994.

Mr Johnson declined to comment on whether Charles was wrong in his comments, adding: “This is about making sure that we break the business model of criminal gangs who are not only risking people’s lives but undermining public confidence in legal migration.”

The Prime Minister’s official spokesman said Mr Johnson “has nothing but respect and admiration for the Prince of Wales, who’s spoken out on a number of issues, not least the environment”.

Home Secretary Priti Patel has said the “vast majority” of those who arrive in the UK through means deemed “illegal” – such as on unauthorised boats or stowed away in lorries – will be considered for relocation.

It is understood that adults will be prioritised for relocation under the scheme, with officials insisting families arriving in the UK will not be split up.