New long-haul seating and layout for British Airways World Traveller and World Travel Plus cabins have been unveiled.

The revamp initially involves new generation economy and premium economy seats on aircraft flying from Gatwick.

The World Traveller Plus cabin in the fleet’s three class Boeing 777s will be doubled from 24 to 52 seats, while Club World capacity will be cut from 40 to 32 seats.

The World Traveller Plus cabin in the fleet’s four class 777s will see an additional 12 seats added.

Heathrow-based 777s will then be fitted with new World Traveller Plus seats from autumn 2019. The changes will see ten abreast seating in economy.

But the new seats will have 50% larger entertainment screens and will initially be introduced across the airline’s fleet of ten long-haul aircraft based at Gatwick.

Six three-class 777s aircraft will be completed by winter 2018, with the four four-class variations finished by summer 2019.

The first routes to see the changes will be to Punta Cana, Cancun and Kingston in Jamaica before being gradually expanded to all 22 of BA’s long-haul routes from Gatwick.

World Traveller cabins will be fitted with enhanced seating, including a six-way headrest with adjustable flaps and movable middle arm rests, seen as useful for customers travelling with children.

The World Traveller Plus design features a new leg and footrest, as well as an adjustable six-way headrest. The new seat also has a cocktail table at the front and in-arm tray tables.

A new Panasonic new in-flight entertainment system – which has the capacity to offer four times as many films, TV and audio – has been updated with larger HD screens.

The screen size will increase from six to ten inches in World Traveller and double from six to 12 inches in World Traveller Plus.

New USB sockets are available at every seat allowing all passengers to charge electronic devices in flight. World Traveller Plus seats also have an additional power outlet socket for UK, US and EU plugs.

Bespoke lighting has been fitted in every cabin and can be set to reflect the time of day, helping to lull travellers to sleep at night and wake them in the morning to reduce the effect of jet-lag.

BA network and alliances director Sean Doyle said: “We are one of the very few global airlines that offers a choice of four cabins for customers to travel in and World Traveller Plus appeals to a broad mix of both leisure and business travellers.

“In response to demand we’re increasing the size of the cabin so we can offer more of these popular seats to our customers, while keeping the cabin intimate and retaining the expert, attentive service that our travellers love.”

The seating revamp follows BA announcing in January a multi-million-pound investment in its World Traveller catering with the introduction of more, better quality food and greater snack options on long-haul flights.

New generation wi-fi across long-haul and short-haul fleets is also being introduced over the next two years.

BA at Gatwick has seen 40% more passengers travelling over the past five years, with numbers increasing from 4.4 million to 6.2 million.

The airline has also increased the number of routes it serves from Gatwick by more than 50% to 74 from 48 in 2012.