Flight-shamed holidaymakers are turning to beach cleans to get over their guilt about the environmental impact of flying, it is claimed.
Thomas Cook said 1,500 of its customers picked up a total of 25,000 items of rubbish from beaches at its destinations this summer.
The tour operator has ordered all 200 of its own-brand hotels to put on regular beach clean activities for guests next year.
READ MORE: Cities could 'reap significant benefits' from e-scooters
Its research indicates that one-third of customers say spotting litter on a beach affects whether they return to a location, while two-in-five holidaymakers are more likely to choose activities which benefit the local community than they were 10 years ago.
Concern about emissions from flying sparked the flight shame movement, which has spread across Europe in recent months.
The Duke and Duchess of Sussex have come under fire for their use of private jets, while teenage environmentalist Greta Thunberg sailed from Plymouth to New York on a zero-emissions yacht.
Thomas Cook group corporate affairs director Alice Macandrew said: "Thanks to Greta Thunberg and other activists, as consumers we're becoming much more aware of the impact that our behaviour is having on the planet.
"This awareness is now filtering into our holiday mindset, with more and more customers wanting to give something back to the destination they visit.
"The popularity of these initiatives show that customers are willing to clean a beach to clear their conscience, and we're now looking to roll this out across our hotel portfolio."
In November 2018, Thomas Cook committed to remove 70 million single-use plastic items from its operations in the UK, on its planes and at its own-brand hotels.
It has partnered with British design firm Wyatt and Jack to convert customers' discarded plastic inflatables, lilos and children's armbands into bags and holiday accessories.