Lumley, who has presented several travel shows, is among a list of signatories to a letter from pressure group World Animal Protection to Tui Group chief executive Sebastien Ebel.
The others are: Alesha Dixon, Bella Ramsey, Deborah Meaden, Evanna Lynch, Gail Porter, Jane Fallon, Mark Watson, Sarah Jane Morris, Richa Moorjani and Rou Reynolds.
In the letter, Tricia Croasdell, World Animal Protection chief executive, said: “We ask Tui Group listen to marine scientists who agree cetaceans cannot thrive in captivity."
Croasdell urged Tui to follow the example set by the likes of easyJet holidays, Jet2holidays, Virgin Holidays, Expedia Group, Booking.com and Airbnb, whom she said – along with governments and tourists – had "said no to cruel captive dolphin entertainment".
"Not doing so will place Tui Group firmly on the wrong side of history when it comes to ending the suffering of these intelligent wild animals," Croasdell continued, repeating her offer to meet with Ebel on the issue.
“We stand ready to help you, as we have with other organisations, to develop an animal welfare policy.”
’Travel’s wave of change on animal welfare’
The letter adds: “There are responsible and sustainable ways to see dolphins and whales in the wild where they belong.”
Celebrities and supporters will take to social media on Thursday (22 August) to call for Tui to end its support of dolphin attractions using the hashtag #NoTanksTui.
TTG has approached Tui for comment.
