EUROSTAR services are returning to normal today after a day of serious disruption on the French side of the Channel Tunnel.

Angry ferry workers staged a wildcat strike from the early hours of the morning in protest at the sale of two MyFerryLink vessels by Eurotunnel to DFDS, which had followed a decision by the British Competition and Markets Authority that Eurotunnel could not be permitted to run ferries.

Some strikers broke into the Channel Tunnel, forcing all trains to stop, while others threw burning tyres on to the tracks on the approach to the portal. As the effect of the blockade worsened, and with all ferry and train services suspended, long traffic queues built up on both sides of the Channel, with the M20 in Kent occupied by hundreds of stranded lorries.

Eurostar trains approaching the Tunnel were turned back to London and Paris, and 'hectic scenes' were reported at St Pancras International.

Many of the estimated 3,000 migrants who occupy a makeshift camp at Calais tried to board the stationary vehicles in the French tailbacks, hoping to reach the UK by hiding in lorries. All vehicle drivers were warned to keep their doors locked.

French police have been criticised for their alleged lack of action, while there were also political clashes. The deputy mayor of Calais Emmanuel Agius accused the British gobvernment of failing to accept responsibility for the crisis at in his city, claiming that the British were "showing that they despise the people of Calais". But British sources countered that the French were failing to control the passage of migrants without papers or travel documents across France, allowing them to reach the Channel coast so that they were better placed to cross to the UK.

Immigration minister James Brokenshire said the situation was 'hugely regrettable', and announced new and tighter immigration controls. He said: "We are putting additional resourcing into the port of Dover to enhance screenings and detections there so that we're looking at this on both sides of the Channel.

"We have been advised that the French authorities are sending further policing to deal with law and order issues, and we will be keeping in close contact with them."

More British Border Force personnel are being deployed in Calais and around the Tunnel terminal at Coquelles, aided by reinforcements at Dover. Mr Brokenshire said these measures were intended to maintain "safety and security and the integrity of the border, which is our absolute focus".

Some of the thousands of travellers who were stranded by the blockade described the effects of the disruption. One lorry driver told the BBC that his working day had been 'virtually destroyed'. He said: "When you're driving in toward Calais there's hundreds of migrants just waiting for you to stop. There have been various times I've been parked in Calais and woke up in the morning, gone to check my vehicle like I normally do, and found out that there's about three or four people in the back and you've just got to say 'out'."

Meanwhile, Eurostar passengers who were waiting at St Pancras said the situation there was a 'shambles'.

Limited Eurotunnel services began running at around 18.00 last night, and Eurostar resumed its timetable this morning.