Tickets will go on sale in the autumn once regulators approve the route, which the carrier hopes to begin operating in spring 2026.

Alaska Airlines’ oneworld alliance partner British Airways already flies the Seattle route, as does SkyTeam’s Delta and its partner Virgin Atlantic.

Seattle is popular with cruise passengers, who use the city’s terminal to embark on northward itineraries.

Alaska Airlines’ flight will also open up more of the US west coast for UK travellers.

Despite its name, Alaska Airlines’ main base is in Seattle, although it has a smaller hub in Anchorage, Alaska’s capital.

The airline, which is the US’s fifth-biggest carrier, has other hubs at Los Angeles, San Francisco, San Diego and Portland, ensuring coverage of much of the US’s Pacific coast.

Launching the London route launch is part of Alaska’s expansion plan following its acquisition of Hawaiian Airlines last September.

This brought Alaska Airlines a fleet of long-haul aircraft, including Boeing 787s, which will be used on the London route.

The fleet will also be used to launch a refreshed Alaska Airlines livery, although the Hawaiian brand will be retained.