Around 200 migrants broke through several layers of security before approaching the tunnel entrance.

As the migrants scrambled down to the final fence line, dozens of police arrived to back up the military.

The migrants and security forces faced off for close to an hour, with the migrants shouting slogans including: "Open the border" and "We are not animals."

One of those trying to break in to the tunnel railhead said he had heard that the UK was about to use the Army and it was their last chance.

Speaking last night, Ibrahim from Eritrea says they wanted to get through before security's beefed up:

Meanwhile, the Irish Road Haulage Association says the Calais migrant crisis is having a detrimental affect on exports.

The body is calling on the Government to join in efforts to bring the situation under control.

It says 90 per cent of Irish exports travel through the French port, and drivers are fearful for their own safety as the face the hundreds of refugees gathered there.

Eoin Gavin European representative for the IRHA describes the scenes in Calais:

The overnight scenes come as Home Secretary Theresa May and France's Interior Minister said the EU should step in to help Britain and France find long-term solutions to the "global migration crisis."

Ms May and Bernard Cazeneuve said the chaos in Calais is not only a problem for the UK and France.

In an article for The Sunday Telegraph, they said: "We are both clear: tackling this situation is the top priority for the UK and French governments.

"We are committed and determined to solve this, and to solve it together. What we are currently facing is a global migration crisis.

"This situation cannot be seen as an issue just for our two countries. It is a priority at both a European and international level.

"Many of those in Calais and attempting to cross the Channel have made their way there through Italy, Greece or other countries.

"That is why we are pushing other member states, and the whole of the EU, to address this problem at root."

A new package of measures has been agreed which will see security ramped up at the Channel Tunnel.

The steps include 200 extra private security guards funded by the UK, French police reinforcements, additional fences provided by Britain and more CCTV.

Downing Street admitted the UK would fund "most if not all" of the new security measures in Calais.

It comes after David Cameron called French President Francois Hollande to discuss the migrant crisis.

The Prime Minister has warned the crisis, which has seen some 5,000 desperate migrants lay siege to the tunnel in the hope of reaching Britain, could last all summer.

Harriet Harman has written to Mr Cameron demanding he ask the French to compensate Britons affected by the chaos in Calais.

Labour's interim leader says the Prime Minister should be doing more to recoup the cost of the crisis to haulage companies, who have seen their vehicles stacked on the M20 in Kent due to disruption to ferry and Channel Tunnel services.

They are estimated to be losing over €9,000 a day as a result of the delays.

"You have failed to initiate any diplomatic pressure on the French government to assess asylum claims and make sure proper immigration procedures are followed," Ms Harman told the PM.

"Instead you have chosen to inflame the situation with incendiary and divisive language, which will serve only to escalate the problem."

A Downing Street spokesman responded: "As the PM has said, playing a blame game is not going to offer a solution for anyone.
"What we are focused on is working closely with the French authorities and taking action to both boost security and reduce disruption for hauliers and businesses.

"We welcome the French police reinforcements, which have helped to strengthen security at Eurotunnel.

"We are already pursuing a comprehensive approach to tackling illegal migration into Europe; supporting rescue operations in the Med, disrupting trafficking gangs and working to stabilise the migrants' home countries."

The Government is considering using car parking space at Ebbsfleet railway station, or the disused Marston airport, to ease lorry stacking on the M20.

The motorway was reopened for normal traffic on Saturday evening.