Eurostar services were delayed again today amid ongoing industrial action by French customs staff.
Customers were complaining of queues of several hours today at the Gare Du Nord.
Eurostar bosses warned people not to travel for a second day in a row. The industrial action is due to last until March 19.
Eurostar said in a statement that customers should not travel "unless absolutely necessary."
The firm said customers can change their tickets to a later date free of charge or claim a full refund.
Four trains were cancelled today; the 13.03, 16.37, 20.34 and 21.03 services.
Three trains are cancelled tomorrow and one train is scheduled for cancellation on Tuesday.
Customers took to social media to vent their frustration today.
One customer wrote online: "Over Two hours in line now. I am utterly disgusted. This was time I could have spent exploring your beautiful city"
Another wrote: "Ridiculous really isn’t it - spent an extra £200 trying to get home plus a shortened weekend in Paris!"
The delays were even worse yesterday with customers complaining of delays of over five hours.
One traveller attempting the trip to London, Tom Halverson, told the Standard: "It is a fairly calm atmosphere for the most part. People are just getting restless. We’ve been in line almost five hours."
His daughter Ally, who is joined by her brother and mother too for their spring vacation, told the Standard she was getting tired and there were no bathrooms to go to either.
She said people were confused and they did not know "when the line will be over and if we'll be able to travel to London tonight".
All unions representing customs officers working at Paris Charles de Gaulle airport also called for strikes until April 1.
Anne Asoulay-Fravel, a customs official from the French General Confederation of Labour union, previously told FRANCE 24: "This movement is going to last."
She said she had never seen so many colleagues involved in a strike.