British police will be deployed to Calais to target trafficking gangs as part of a fresh drive to tackle the migrant crisis.
Officers from the UK will be based in a new "command and control" centre alongside their French counterparts and Border Force personnel at the port town in northern France.
Plans to set up the operation are part of a new deal between France and Britain which will be signed in Calais by Home Secretary Theresa May today.
Officials said the move was aimed at disrupting organised criminals who attempt to smuggle migrants illegally into Northern France and across the Channel by ensuring intelligence and enforcement work is more collaborative.
The work of the police contingent will be led by two senior "gold" commanders - one from each country.
They will report regularly to the Home Secretary and her French opposite on the extent of immigration-related criminal activity on both sides of the Channel.
The two countries will also work jointly to ensure networks are dismantled and prosecutions are pursued, sources said.
Mrs May will visit Calais to confirm a joint declaration with her French counterpart Interior Minister Bernard Cazeneuve.
Fresh measures included in the new agreement include:
:: The deployment of extra French policing units
:: UK resources will be invested to make the Eurotunnel railhead secure through fencing, CCTV, flood lighting and infrared detection technology
:: Security will be tightened within the tunnel itself, with Eurotunnel helped to increase the number of guards protecting the site.
:: A new "integrated control room" covering the railheads at Coquelles will be created.
:: A security audit will be carried out by specialist French and British police teams to underpin the design of the improvements.
:: Additional freight search teams, including detection dogs, will be deployed.
The British Government has already pledged £20 million over the past year to improve defences around the port of Calais and the Eurotunnel terminal after an unprecedented wave of incursions by those attempting to reach the UK.
Up to 5,000 people are estimated to be in Calais. A number of migrants have died attempting to cross to Britain.
The crisis appears to have abated since its peak earlier in the summer. Eurotunnel said earlier this week that the number of migrants trying to get into the terminal has fallen to around 150 a night, down from a high of 2,000 at the end of July.
However, concerns have been raised that closing off openings at Calais will prompt migrants to attempt to make the crossing by different routes.
Keith Vaz welcomed Mrs May's visit, which is the first by a government minister since the crisis escalated.
However, he added: "We must be aware of the dangers of the domino principle. Closing off one route will only mean the problem moves to another port.
"There is already evidence of more illegal activity around Dunkirk, Zeebrugge and the Hook of Holland. We need agreements with countries across the north coast to stop this situation developing before we see Calais-like crises spring up at ports across the continent.
"This remains an EU problem. If we do not take control urgently, by the end of the year we could easily see the number of migrants reaching Europe equivalent to the populations of both Malta and Luxembourg combined."
The situation at Calais is part of a wider migration surge into Europe, mainly from North Africa and the Middle East.
Figures released today showed the number reaching EU borders has hit a record high, surpassing 100,000 in July.