Virgin Atlantic and Delta are running a joint advertising campaign to celebrate the fifth anniversary of their transatlantic partnership.

The airlines are also marking the five-year milestone by offering a series of “sky-high surprises” for customers throughout February.

Customers travelling on selected flights between Heathrow, Atlanta, and New York-JFK will receive treats from each airline such as cocktails, Love Heart sweets, cookies and Virgin Atlantic Happy Socks.

Their partnership means airlines now operate up to 74 daily non-stop flights between the UK and US – nearly 20% more than in 2014.

The airlines have also invested in new technology, including automated bag-drop facilities at Heathrow and Gatwick; real-time bag-tracking via the Delta app; and biometric security at Atlanta airport.

The airlines have co-located at eight airports, helping punctuality at Heathrow, and making it easier for customers to connect between flights to more than 200 destinations in the US.

Juha Jarvinen, commercial executive vice-president for Virgin Atlantic, said: “We’re really proud that over 24 million customers have chosen to fly with Virgin Atlantic and Delta across the Atlantic since the start of our partnership five years ago.

“This year, we’ll take the next step in our journey through an expanded joint venture with Delta, Air France and KLM.”

Corneel Koster, Delta’s senior vice president EMEAI, said: “The partnership has gone from strength to strength and is hugely popular with our customers. The original deal was a game-changer for Delta transforming our ability to compete on key transatlantic business routes to and from London Heathrow, as much as providing Virgin Atlantic unparalleled access to Delta’s US network.”

In May 2018, Air France-KLM, Delta and Virgin Atlantic signed agreements to combine the existing transatlantic joint ventures.

This transaction is in the process of regulatory clearance.