P&O Cruises and Cunard have pledged to stop using all single-use plastic by 2022.
Carnival UK president Josh Weinstein said the operator’s ships already have strict rules in place over recycling of the plastic.
However, he admitted more could be done, adding: “We are in discussions with our suppliers to try to influence the removal of single use plastic in products such as straws, water bottles and food packaging wherever possible, as well as reviewing our wider sourcing strategy of the most environmentally friendly products across the board.
“Programmes such as Blue Planet have shone a light on the impact plastic can have on our seas and it is our responsibility, as an ocean-going cruise line, to take action now, however many hurdles we have to face along the way.
“The ocean is a fundamental part of our business but more importantly its preservation and that of the surrounding shores is critical for our future and that of future generations.
"We, as well as our guests, have a duty to respect and protect it as part of our wider environmental protection.
“The second XL class ship for P&O Cruises, which is fully powered by LNG and one of the most environmentally advanced ships in the world, and the new Cunard ship will be launched in 2022 so this intention goes even further in our ongoing quest for environmental protection.”