This is the shocking moment migrants surround a passenger coach as they tried to smash their way into the back of a lorry before it boarded a ferry at Calais bound for the UK.

The dramatic footage was filmed by a passenger, who was travelling from the French port town to Dover.

As vehicles begin to queue up as they enter the port, one of the passengers on the coach begins filming as a large group of migrants approach them and one of the lorries, The Daily Mail reports..

After opening the truck's back doors, at least two men can be seen climbing inside the vehicle before another four join in.

They climb over the freight inside and are forced to hold on as the driver pulls away, seemingly unaware of the stowaways in the back of his lorry.

At the same time, the tour guide on the bus can be heard trying to reassure the shocked passengers.

He says: 'Basically they are not allowed in the country.

'Don't panic guys, we have locked all of the doors. Try not to panic guys.'

One of the shocked passengers asks: This is hardcore man. Do they not police this? Someone replies: ‘No.’

Eventually the other migrants who have crowded around the lorry slam the back doors shut after appearing to realise they too are unable to climb on board.

Meanwhile several others begin pulling at the side of the truck as the gasps from the coach passengers are audible with one remarking: 'This is what we've seen on TV.'

The migrants then start to circle the coach, and a burly tourist is asked to come to the front apparently to help guard the door.

The footage of last week's incident has been uploaded to Youtube by coach passenger Jenny Adams, a bank worker from New Zealand.

She has been spending the past year travelling around the world with her husband Dave, 26, with the pair keeping a blog. 

He wrote: 'Returning from Europe yesterday we encountered a group of refugees who’ve set up camp just outside the Calais port.

'The refugees, who are desperate to cross the channel into the UK for better work opportunities and safety as they escape their own countries, began rioting by setting up road blocks and began climbing into the hollows of trucks, breaking windows and opening side panels looking for supplies.

'Behind our coach many of the migrants began to climb over the car of a solo elderly woman which would have been very traumatic.

'Jenny caught some of the action on camera but had to stop filming when one of the refugees sees her filming and threatens to throw a rock through the windscreen.

'We were really lucky that our driver had locked our luggage compartments underneath the bus or our belongings would be long gone and that they did not figure out the emergency open switch on the back door which would have allowed them to board.

'Generally the refugee camps tend to be harmless but on this day they group seemed to have an extra level of desperation.

'We’d heard that a couple of days ago there had been an altercation within the camps that led to a couple of deaths…perhaps this reaction is a result of that.

'Moments after the video ends the migrants began to flee as French police arrived in riot gear, searching trucks and directing the refugees back towards their camp.'