The decision is intended to make it easier for customers to “manage their travel plans” including last-minute flight changes.

Delta will transfer its Atlanta, Detroit, Minneapolis, Salt Lake City and Philadelphia flights from Terminal 4 to join its services to New York-JFK, Boston and Seattle that already operate from Terminal 3.

Nat Pieper, Delta’s senior vice president Europe, Middle East and Africa, said: “Our joint venture with Virgin Atlantic is all about making it easy for our customers to connect between our airlines and having our Heathrow service under one roof is crucial to delivering a synched-up,

more convenient service.

“This marks a major milestone in our joint venture.”

In total, Delta will operate 11 daily flights to eight US cities non-stop from Terminal 3.

Erik Varwijk, executive vice president commercial at Virgin Atlantic, said: "Once the switch goes ahead, our customers can enjoy an even more seamless experience flying from or through London.”