The impact of chaos in Calais is set to last all summer, David Cameron has warned as he launched the Government's latest attempt to get a grip on the crisis.
Attempting to take charge of the response after returning from his visit to south east Asia, the Prime Minister called the situation "unacceptable" and declared: "We are absolutely on it. We know it needs more work."
The Prime Minister pledged fresh measures to boost security in the French port - including extra sniffer dogs and fencing - but critics claimed they were a "sticking plaster".
Options to relieve the chronic traffic on the M20 are being considered but specific locations are yet to be confirmed.
Laws including new powers to tackle illegal working will be fast-tracked, while Britain and France plan to put on flights to return migrants to their home countries.
However, Mr Cameron admitted: "This is going to be a difficult issue right across the summer."
The ominous prediction comes as police and social services are already struggling to cope with the impact of the events across the Channel, while businesses, lorry drivers and residents have been hit by the resulting travel chaos in Kent.
It came after a fourth night of disruption at the terminal in northern France, while migrants' desperation to reach Britain was laid bare in an extraordinary picture showing two clinging to the top of a lorry as it arrived at Folkestone in the early hours of Friday.
There was more disruption in Calais today as striking ferry workers reportedly burned tyres.
Speaking in Downing Street after chairing a meeting of the Cobra emergency committee, Mr Cameron said no action would be ruled out. He has assembled a team of senior ministers to lead the response.
Britain will work "hand in glove" with the French to tackle the problem, the Prime Minister said.
"The situation is not acceptable and it is absolutely this Government's priority to deal with it in every way we can," he said.
"We have got people trying to illegally enter our country and here in Britain we have got lorry drivers and holidaymakers facing potential delays."
The new Immigration Bill, which includes powers to tackle illegal working and abuse of the asylum system, will be "sped up" and introduced as soon as Parliament returns, Downing Street said.
Efforts to reduce the number of migrants in Calais – estimated to be as high as 5,000 – will also be stepped up.
A No 10 spokeswoman said: "That includes stronger cooperation on returns, with UK funding and joint flights to countries like Sudan."
Britain will provide more fencing to secure the platform at Coquelles in addition to equipment already promised. More border force search and dog teams will also be deployed.
The spokeswoman said "urgent options" are being pursued by defence and transport planners to create alternative parking zones to alleviate the pressure in Kent.
This may include a temporary freight overspill at Ebbsfleet, while increasing ferry capacity on different routes is also being explored.
Richard Burnett, chief executive of the Road Haulage Association, said the measures are "not enough" to tackle the "out of control" crisis.
"They are just sticking plasters in terms of trying to resolve this problem," he told BBC News.
James Hookham, deputy chief executive of the Freight Transport Association, said he was pleased the issue was "on the Prime Minister's desk", adding: "Let's just hope he can manufacture a genuine solution to this."
He called for Britain to press France to make the port a "strike-free zone".
"The wheels really came off the wagon two weeks ago because the ferry workers went on strike," he said.
Former Foreign Secretary Jack Straw said the borderless system known as the Schengen agreement was at the heart of the problem.
"You now see the price that Europe is paying, as well as the United Kingdom is paying for this completely open border arrangement," he told BBC Radio 4's World at One.
Calais police union representative Gilles Debove said there is a "real attraction" for migrants to reach Britain, saying they can "can work without a residency permit or identity card and they can work illegal".