Eurotunnel said it expects normal services through the Channel Tunnel to resume after a day of disruption caused by "migrant activity" on the French side of the tunnel.
The operator, which apologised to passengers who had endured delays of up to five hours on one of the busiest travel days of the year, said the backlog of passengers to France should be cleared overnight.
John Keefe, a spokesman for Eurotunnel, said the company hoped that less freight traffic travelling from France overnight would mean fewer disruptions from migrants, allowing a regular service to return by this morning.
Eurotunnel has no delays before check-in, but due to an earlier incident there is a 30-minute wait at the terminal itself. Services from the French side are running to schedule.
Operation Stack, which closes the M20 in Kent coast-bound to cars between junctions 8 and 11 to hold waiting freight traffic, remains in place following the high volumes of freight traffic seeking to use Channel ports.
Mr Keefe said on Saturday night: "The night is obviously when the migrants come and disrupt services at the French terminal. Because there is less freight traffic on a Saturday night there is normally less migrant activity - there is less disruption expected because there are fewer opportunities for them to cross.
"If that proves to be the case then hopefully we will start tomorrow morning without a delay."
The Port of Dover also remains open, with both P&O Ferries and DFDS Seaways operating a full service.
Earlier on Saturday motorists were stranded in lengthy queues as they waited in traffic.
Issues with migrants entering the Eurotunnel terminal at Coquelles have been a nightly occurrence in recent weeks, causing problems with services crossing the channel.
There were delays to the service on Thursday when the body of a suspected migrant was found on the roof of a Eurotunnel train at the Chunnel terminal in Folkestone.
An estimated 5,000 migrants displaced from countries including Syria, Libya and Eritrea are now believed to be camped in and around Calais.
Mr Keefe said Eurotunnel has spent 150 million euro (£106.1 million) since 2000 on security, an average of 10 million euro (£7 million) a year.
But it has already spent 13 million euro (£9.2 million) on security in the first six months of this year, he added.
Freight transport chiefs have said Britain's freight industry is losing £750,000 a day because of the huge problems lorry drivers have faced this summer trying to cross the channel.