Striking ferry workers blocking access to Calais port in northern France agreed on Wednesday to let some boats through, partly lifting a blockade in its third day.
Workers at ferry service MyFerryLink are trying to prevent job cuts after their company was sold to a Danish company earlier this month.
They agreed to let some boats go after their representatives were invited to meet with Transport Ministry officials on Thursday morning, following a threat to disrupt traffic through the Channel Tunnel for 48 hours.
"We've accepted to lift the blockade of the port from 20:00 (1800 GMT) to let P&0 boats through one by one," union official Eric Vercoutre told journalists.
The threatened disruption of Tunnel traffic for Thursday and Friday would coincide with a surge in travel at the start of school summer holidays if the workers went ahead.
The protesters had already blocked the tunnel's entrance for several hours on Tuesday by setting fire to tyres thrown onto railway tracks.
MyFerryLink was previously owned by Eurotunnel, the company that operates the undersea cross-Channel rail link.
Migrants from Africa and the Middle East seeking to slip into Britain tried to profit from the strike to stow away on waiting trucks.
Dozens of migrants sat on the roadside around the port in the hope of sneaking aboard one of the vehicles, lined up bumper to bumper to limit their chance of getting in the back doors.
Adam, 36, a Sudanese migrant who fled the war-torn Darfur region, said he had nothing to lose and hoped to take advantage of the chaos.
"I am from the Zaghawa ethnic group and I no longer have a future in Sudan, although I have graduated," he said. "I have been in France for the last two months and our life these days is very difficult. I hope to arrive to the UK because I will have identification documents quicker than in France."
Calais is one of the flashpoints of the immigration crisis facing European Union countries, who are struggling to agree among themselves how to deal with the thousands of migrants heading their way to escape conflict or poverty.
Up to 3,000 migrants are estimated to be amassed around the port. Many want to get to Britain because they speak English, have family connections or are convinced they stand a better chance of getting a job there.
"Some try to get on the lorries by all possible means. Sometimes they cause damage to the freight we carry and then the client may refuse to pay for the freight we ship," said a 58-year-old truck driver who gave his name as Elso.
(Reporting by Matthias Blamont; Writing by Brian Love and Leigh Thomas; Editing by Larry King)