British troops could join efforts to ease traffic congestion in Kent as the migrant crisis shows no sign of abating.
The Ministry of Defence (MoD) is understood to be in the early stages of developing plans which could involve using land owned by the department to free up space on the M20.
The Daily Telegraph said MoD land around Folkestone could be used as a temporary lorry parks.
The source said a decision on the plans would be "taken in due course", adding they were led by the civilian authorities rather than military.
David Cameron, who has returned to the UK after a four-day tour of south-east Asia, will head to Westminster to chair a meeting of the Government's emergency Cobra committee this morning.
It is understood he will ask ministers and officials to see whether more can be done to address the situation at the port and the Channel Tunnel railhead at Coquelles.
The meeting comes after Mr Cameron blamed the chaos at Calais on a "swarm" of migrants crossing the Mediterranean and travelling through Europe.
French security and police were again dispatched to prevent desperate migrants from gaining illegal access to the Channel Tunnel following a week of unrest in Calais.
The situation in Calais has threatened to bring the cross-Channel haulage industry to a halt, with long queues at border control points in England and France.
As the situation rumbled into a fourth night of disorder, up to a hundred migrants roared as they steamed through police lines at a petrol station near the terminal to gain access to the tunnel.
French gendarmes and riot police at first were overwhelmed by the numbers coming at them but were able to gain control of the situation.
Officers, some with their batons drawn, formed a cordon backed up by riot vans.
But they could not prevent the men, women and children, mainly from East African and Arab countries, from bringing the road out of the tunnel in Coquelles to a standstill.
They watched as three or four teenage migrants climbed over a fence but later came back when they realised they had hit a dead end.
Afterwards Eurotunnel said its French platform was unavailable due to "security reasons".
A spokesman said: "Due to overnight activity around our French terminal, timetables are disrupted from both directions."
Another night of drama in Calais has increased fears the UK's already under-pressure social services will be pushed to breaking point as the number of asylum seekers increases.
Paul Carter, leader of Kent County Council, has met officials from the Home Office to highlight the impact of hundreds of minors arriving unaccompanied at the port of Dover.
The number of young migrants in the local authority's care has almost doubled to 605 in the last three months, leaving it with a multimillion-pound funding gap.
Mr Carter said the "massive logistical exercise" of supporting those aged under 18 who make it to the UK is putting an "enormous strain" on children's social services.
"We've got two issues," he said. "One is having to contend with Operation Stack and the main arterial route, the M20, being closed in both directions.
"But also, local government has statutory duties to provide care for unaccompanied minors under the age of 18 and those numbers have escalated dramatically in the last four to five weeks.
"That is connected with more migrants getting on to trains and in some cases boats and presenting at Folkestone or Dover seeking asylum. If they are under 18 we have to care and provide for them.
"About a year ago it was running at about 238 unaccompanied minors under the age of 18 that we were supporting. That is now well over 600 and rising day by day, week by week."
He said the council faces a shortfall of £5.5 million in care costs.
Earlier David Cameron blamed the Calais crisis on a "swarm" of migrants crossing the Mediterranean.
Speaking in Vietnam, the Prime Minister said the French had sent an extra 120 police and the UK was investing in fencing and security measures at the Channel crossings in Calais and Coquelles.
But the Government has resisted mounting calls for the army to be deployed.
Nine people have been killed attempting to cross the Channel in the last month, according to Eurotunnel.
Bernie Gibson, managing director of Compass Fostering, said social services including those in Kent were struggling to cope with the numbers of children arriving as asylum seekers.
She told the BBC Radio 4 Today programme: "We have been working with young people that have come from areas like Morocco, Eritrea. We have seen cases of these young people taking long journeys, taking lengthy crossings and coming under lorries as a result of traumatic experiences in their country of origin.
"We are often approached by local authorities like Kent to see if we have a safe home, a safe place, so these young people can reflect about their experiences and just receive the basic care children should receive.
"The challenge to find foster carers nationally for Compass is challenging anyway but imagine on top of that these children are very traumatised, they don't speak English. Often they come from different cultural experiences.
"But these people do step forward and they can step forward."
She added: "Our referrals have increased significantly over the last year. This time last year, we were receiving around 34 referrals in one month - that's increased to 140 referrals. That's a nearly five-fold increase."