They should be lined with snacks and pre made meals.

Items out of stock Tuesday included sandwiches, salads and a turkey tortilla with curry.

M and S said new trade rules since Britain left the EU single market were causing delays to deliveries.

In a statement to Reuters, it said that some products were taking longer to reach shelves, but that it was working on the problem with suppliers.

M and S Ready meals are popular in Paris as they cater to and eat on the go market that is under served in France.

Ah country better known for hope cuisine.

Since January 1st goods traveling between the UK and France have been subject to new customs checks.

But the flow of trade has so far bean smoother than some expected.

Trucking operators say there has been no congestion at the key channel ports over in England and Calais In France, however, traffic flows are currently lower than usual, meaning bigger tests may lie ahead.