Passengers trying to cross the channel are facing further disruption due to "migrant activity" in Calais.
Eurotunnel briefly suspended services on both sides of the channel just before midnight on Friday. Services have now resumed, subject to delays.
In a tweet just before 03:00 BST, the operator said there were delays of up to three hours for passengers heading to France from the UK.
There are delays of up to an hour for people travelling from France.
On Friday, the cross-Channel rail operator said police were being called each night to remove migrants from its Coquelles base.
Passenger and freight services were hit by delays as the firm tried to run services on one of the busiest days for holiday travel.
Eurotunnel said the migrant activity was well organised and planned, with people so desperate to reach the UK they were prepared to throw themselves at trains travelling at 90mph.
On Thursday, the body of a teenager was found on a train at the Eurotunnel terminal in Kent.
Operation Stack, which involves parking up lorries waiting to reach France, has remained in place in Kent to deal with the cross-Channel disruption and police have warned it could continue until Sunday.
Lorries have now been parked on the motorway for a total of 19 days over the past three months.
On Friday, talks were held between MPs, Kent County Council, Kent Police, cross-Channel operators and hauliers on how to deal with the disruption.
It is thought there are now about 5,000 migrants in Calais.
Le Shuttle, which takes passengers across the channel in cars, caravans, buses or other vehicles, usually operates up to four crossings an hour.
The first Eurostar service, which carries passengers only, is due to depart from London at 06:18 BST.
(BBC)