Some 150 migrants have caused chaos for Channel Tunnel services, as they attempted to storm the terminal in Calais.
The people entered restricted areas overnight, causing severe delays and cancelling trains, according to operator Eurotunnel.
The company called for more security, saying that action needed to be taken to prevent a large-scale crisis.
Despite the disruption, passenger services have now returned to normal, but freight operations are still facing delays. There are queues on the M20, as UK police have started stage two of operation Stack – which queues freight traffic on the M20.
Up to 150 migrants stormed the tunnel, which caused disruption to services leading to delays and cancellations for customers.
Eurotunnel wants immediate action from authorities to protect the tunnel - not enough is being done to stop the migrants
The desperation of people to enter the UK is partly down to the greater number of refugees in Europe due to conflicts in Syria and north Africa. Several reports have shown the living condition of people making it as far as Calais to be squalid.
Martine Devries, from Médicins du Monde, told the Guardian conditions in France were becoming more desperate:
There are more people and they are becoming more desperate and are taking more risks. Last year people would only make attempts to get on to lorries at night, now there are so many and they are so desperate people are trying in broad daylight.
The crisis in France is putting stress on lorry drivers, who face the constant fear of stowaways. The pressure has caused some to consider leaving their jobs.