The vessel, which will be built by Meyer Weft shipyard in Germany, will be delivered in 2022.

P&O said it would be similar to its sister ship, which is due for delivery in 2020 and would become the largest built specifically for the UK market.

It added that it would follow a “green cruising design”, and be powered by Liquefied Natural Gas, which significantly reduces air emissions and is described as “shipping’s most advanced fuel technology”.

Carnival UK president Josh Weinstein said: “We are seeing the momentum in awareness of cruising both across the media and in our national psyche... These two next generation ships for delivery in the next four years are real and tangible evidence of our absolute optimism for future growth.”

P&O Cruises senior vice president Paul Ludlow added: “We have a bold and ambitious vision for P&O Cruises to become Britain’s number one holiday choice and we can only do that by increasing our fleet. The build for our 2020 ship begins this spring and it will offer all generations of British guests the holiday of a lifetime on the next generation of P&O Cruises ships.

“In four years’ time when her sister ship is launched, adding an additional 22% capacity, we will see an even greater rise in the popularity of cruising across all demographics and all age ranges including both Millennials and Generation Xers.”

“The first of our new ships will go on sale in September and we will be announcing key elements of the design and build this year.”