A 5mph rolling roadblock has been set up by hauliers and farmers on the A16 motorway, the main route to Calais Port and the Channel Tunnel.
A blockade of lorries and tractors held up traffic on the roads around Calais with a "go slow" protest against the "Jungle" migrant camp.
A convoy of trucks and tractors set off from Dunkirk to the north, while another made its way from Boulogne to the south at 7.30am local time on the A16, which runs along the edge of the town.
They are set to converge near the entrance to the Channel Tunnel and ferry terminals.
No traffic was being allowed to pass the blockade and police were stationed at the junctions, apparently to stop vehicles joining the motorway.
Hundreds of protesters also marched on foot along the road leading directly to the port.
Protesters have been gathering in Calais this morning ahead of a planned demonstration against the "Jungle" migrant camp.
British cross-Channel travellers have been warned they face major disruption as French shopkeepers, police, unionists and farmers join hauliers in calling for the northern section of the camp to be demolished.
A trade association has warned drivers will stand their ground until they see action to dismantle the camp.
ITV News Correspondent Dan Rivers is in Calais:
A few hundred about to march on the motorway to link up with convoys of truckers and tractors enforcing a 'go slow' https://t.co/mMdRZ6LKBa
An Oxfordshire driver is warning holidaymakers at Calais to be extra careful after his car was seriously damaged when migrants threw a concrete boulder through its window. Rhys Williams says if his grandchildren had been in the vehicle, they could have been seriously injured or killed. The 53-- year-old says migrants are taking more desperate risks as they attempt to reach England. Penny Silvester reports.
Few of us can forget those haunting images of migrants, clinging to overcrowded boats, risking their lives to escape persecution.
But how should we respond to their pleas for help?
That's a question which children at a primary school in Sussex have been exploring, using the ancient art of Origami, or paper folding.
Malcolm Shaw spoke to Bern O'Donaghue of Refugees Crossing, Alex Ntung from Migrant Help UK, and Susannah Singh of Christ Church CE Primary School, St Leonards.
Border Force officers have detained three suspected migrants spotted in a boat off the coast of Dover, thought to be destined for the UK.
The trio, who are believed to be Iranian, were initially spotted by a passing ferry this morning. Officials intercepted them after being contacted by the coastguard.
A Border Force spokesman said the three were travelling in a "small boat" and were wearing life jackets.
Royal Naval ships could soon be patrolling the Channel to intercept an increasing number of migrants trying to reach the Kent and Sussex coast. It's been reported that the Border Force, which is responsible for protecting Britain's borders, has asked the Ministry of Defence for more support saying that cuts in staffing have left it struggling to cope on its own. It follows the discovery of 18 Albanian migrants in a dingy off the coast Dymchurch just over a week ago. Tom Savvides talks to Kevin Mills from the Public and Commericial Services Union and the MP for Hove, Peter Kyle.
They had an inflatable boat, and a mobile phone - but no map, lifejackets. nor any safety equipment.
Lifeboat crews said two Iranian men who were paddling a dinghy from France to Kent were lucky to be alive.
Derek Johnson reports from Dover.
Video report: this picture shows 25 people - including five children - found in the back of a truck near the Dartford Crossing. Twenty six others were found in a lorry carrying thousands of pounds worth of peppers to a wholesalers in Canterbury.
Kent Police were called this morning to reports of migrants in the back of a lorry in Coldharbour Lane, Canterbury.
Officers and Secamb attended and approximately 26 migrants have been located. They will be handed over to Home Office Immigration Enforcement to be processed. One woman has been taken to a local hospital for treatment.
Officers were also called to a report that suspected migrants had been found in the back of a lorry in Bridge Close, Dartford, at 9.18am on Monday 21 March, 2016. It was reported that there were 26 people in the lorry, 21 adults and five children.
Officers attended the scene and the migrants have been handed into the care of Home Office immigration enforcement.