Ministers should consider bringing in the Armed forces to help UK border officers who face being overwhelmed by the influx of migrants across the Channel, says a former head of Border Force.

As the number of migrants to reach the UK in small boats this year hit 4,300, Tony Smith, former director-general of Border Force, said it was clear the current set-up was "not fit for purpose".

He said the Home Office should "stop pretending" it could halt the flow of migrants, accept the influx would continue for the foreseeable future and put in place a new "command centre with proper reception facilities" to cope with the numbers arriving on the south coast.

He said Border Force officers risked being overwhelmed by the steady flow of hundreds of migrants they have to process on a daily basis at Tug Haven in Dover in a temporary marquee, and by a forecasting system for crossings based simply on whether it was good or bad weather.

Overcrowding also means migrants are not being immediately tested for Covid, leaving "officers feeling very nervous that they will catch it", he added. "It feels a bit chaotic to me," he said.

"There doesn’t seem to be a long term masterplan which is about accepting that this is going to be a feature of our lives for the foreseeable future and stop pretending that we are going to be able to stop this.

"I would be pressing for a more concentrated strategic management plan based on the fact that we have not been able to stop the boats.

"That should still be our political ambition, but the plain fact is that without an agreement with the French to take them back, we are not going to be able to do instant returns back to France.

"I would feel more comfortable if, first, we accept this is an ongoing process and, second, we have a joint agency approach that could include military, police and a full range of UK assets to support the defence of our border and management of irregular migration because I don’t think we are coping."

Mr Smith cited his experience of working with the military when he was gold commander overseeing the 2012 London Olympics and hundreds of soldiers were deployed to bolster security after G4S failed to provide sufficient guards.

"I was delighted to go into meetings with the military, people who have a huge range of capabilities. They can build a warehouse in a day. They are awesome. The Home Office cannot do that by outsourcing to private companies," he said.

His comments came after a Border Force vessel was said to have entered French waters to pick up migrants in a boat and bring them back to the UK on a day when more than 300 made the crossing.

Meanwhile, Kent County Council warned its children’s services were at breaking point after being overwhelmed by a record 242 unaccompanied Channel child migrants this year. The council is threatening to sue the Government over its failure to ease the crisis.

Roger Gough, the Conservative-controlled authority’s leader, said the Home Office had promised last year to reform the system to disperse more of the children nationally so that Kent’s services would not be put under the same unreasonable strain this year.

Kent currently has nearly double the number of unaccompanied asylum-seeking children (UASC) children in care than the Government says it is safe to have. This year it has already to cope with 60 more migrant child arrivals than at the same time last year.

A Home Office source said it did not believe the Army was needed as the Border Force were receiving the additional resources where necessary.

"I am not sure what role the army would provide that Border Force are not already providing," said the source.