Eurostar last night confirmed it will not be running any passenger services tomorrow.
The company also said that the problem caused by the wintry weather which led the operator's trains to break down in the Channel Tunnel has been identified.
A spokesman for Eurostar said: "As a result of the test runs that were conducted, we now understand the cause of the disruption over the weekend and have identified the modifications that are required."
Thousands of passengers were trapped in the Tunnel for hours on Friday night and yesterday.
The spokesman said screens and shields fitted to the trains to stop snow getting into the electrics had failed and needed to be improved.
He said: "We have already started making the modifications and to ensure that these new protection measures work effectively we are conducting a further series of test runs.
"Our priority is ensuring that when we resume services we provide our customers with a robust and reliable operation."