Eurostar has asked travellers to avoid travelling on its trains unless their trips are essential.
The company has imposed a “very restricted” timetable following a fire in the Channel Tunnel last week.
A statement by the company warned that travellers could face long waits before boarding and journey times could be significantly longer.
“All travellers with non-essential journeys up to Sunday September 21 can get a refund or exchange their tickets for travel at a later date,” the statement said.
Eurotunnel the operator of the Channel Tunnel is carrying our repair work following the fire which broke out on September 11.
Teams from France and Britain spent more than 16-hours working in shift to bring the blaze under control in temperatures of 1,000 degrees centigrade.
Thirty-two people were led to safety via the tunnel's central pressurised safety tunnel after the fire broke out on a heavy goods train heading from France to the UK.
French authorities have said the cause was a heavy goods vehicule carrying phenol – a toxic product – that was travelling from France to Britain.
For more information visit the Eurostar website.