ITV News gains access to Eurotunnel's security operation to see CCTV of migrants storming the terminal

Eurotunnel's sale-pitch is "speed, reliability and frequency of service". Since the summer its services have been subjected to frequent delays as migrants have tried to reach Britain via the tunnel.

At one point in July 2,000 people day were attempting to access the terminal either by lorry or by climbing the fences.

The British government has since given Eurotunnel £7 million to spend on a new inner perimeter fence, more guard dog patrols, lights and cameras.

A new lorry park has been opened on site, making it more difficult for people to clamber aboard or access the rear.

But as security has tightened and opportunities have narrowed so attempts to break through have become more desperate and determined.

Eurotunnel allowed ITV News unique access to the company's CCTV control centre in Calais where several hundred remote cameras are trained on twenty miles of perimeter fence.

While we were there a group thirty one people cut their way through a section and dashed towards a moving freight train. They managed to board it only for the train to slow to a halt as it arrived in Calais.

On 21 of the last 30 days Eurotunnel's services have been disrupted due to security breaches. We were shown a recording of the most serious. Just after midnight on October 3rd a group of more than two hundred people broke through the perimeter fence.

Stones were thrown at Eurotunnel's security guards, some of whom retaliated. 113 migrants reached the tunnel entrance and walked eight miles along the track - one third of the way to the British side - before being captured by french police and removed, free to return again.

Since the delays began in the summer ferry operators have reported a surge in bookings.

Tomorrow Eurotunnel will tell us how its been performing. Today Eurotunnel services were briefly suspended for a third consecutive day due to "intruder activity" but Lord Peter Levene, one of company's British board members, is upbeat.

Last year was a record year for Eurotunnel, for both freight and passenger services. This year has been more challenging. A company Lord Levene admits was once a "basketcase" is now a member of the CAC 40 - the French equivalent of the FTSE 100.

In the space of the last twelve months the number of migrants living in camps known as "the Jungle" on the outskirts of Calais has grown from 600 to 6,000. Eurotunnel wants the camps closed down and a more determined effort made to sort economic migrants from refugees. But the British and the French governments don't seem to agree on how best to proceed.

The people living in the camps come from Afghanistan, Sudan, Eritrea, Somalia, Iraq and Syria. Many feel they can't go back, Eurotunnel security prevents them moving forward and winter is closing in.

Lord Levene argues that the "real solution" is finding a way of persuading others not to join them, of offering them hope, opportunity and security in their homeland. "Most of them don't want to come to Britain" he told ITV News "they're desperate." As he also acknowledges a "real solution" maybe years away.