British TV icon Paul O’Grady is urging travel operator Thomas Cook to stop selling tickets to SeaWorld.
The presenter teamed up with animal rights charity PETA to send a letter asking the agency to remove the amusement park from its promotions.
He wrote: "Selling tickets to SeaWorld condemns orcas to a life sentence in a barren prison cell.
"We know so much more about wild animals today than we did decades ago...I hope you’ll agree that we can no longer in good conscience continue to exploit them for human entertainment.
"I hope Thomas Cook, as the UK’s oldest and most renowned travel provider, will join the growing list of institutions which have severed ties with SeaWorld. Until then, I won’t book it – I won’t Thomas Cook it."
Blackfish revealed inhumane practices at the park
According to PETA: "The letter notes that at SeaWorld, young orcas are separated from their loving mothers – with whom, in the wild, they often spend their entire lives.
"In nature, orcas travel up to 100 miles a day, but in captivity, they have no choice but to swim in circles in tiny tanks.
"The resulting frustration may cause them to chew on concrete walls or attack one another. At least 41 orcas have died at SeaWorld –none of old age."
The letter follows news that the park's CEO Joel Manby has resigned following declining ticket sales.
SeaWorld has struggled to attract visitors since 2012 documentary Blackfish revealed grim practices at the park.
According to the organization: "Manby agreed that this is the right time to identify a new CEO as the company enters its next phase of intensified focus on execution and growth."
According to reports, the company has lost around $415 million dollars over the last two years.