Vivid Travel has suspended all operations, citing the ongoing effects of Covid-19.
All 10 members of the operator’s staff are set to lose their jobs, Vivid has confirmed.
“We have not been able to operate any trips since March and our destination countries remain closed to arrivals," said managing director Kane Pirie.
"I am uneasy entering into new contracts with customers which we cannot fulfil until the crisis is resolved."
Pirie, who founded and led the Right to Refund campaign, said the current market "was not compatible" with Vivid’s "100% commitment to refunds".
Throughout the crisis, he has been a vocal critic of the delays consumers have faced receiving refunds, and of Abta’s makeshift refund credit note regime.
The CAA has since confirm RCNs do carry the same financial protection as the original booking.
“We now have airlines and other suppliers operating regardless of Foreign Office advice," said Pirie. "In this market, trading is reduced to gambling.
"If the trip runs, we might make a small margin, but if it does not, we could incur a significant loss.
"Some of the larger OTAs are now refusing to cancel / refund in that situation, but we have a different relationship with our customers.
"The current market is not compatible with our 100% commitment to refunds.”
Pirie said all bookings had been cancelled, with customers due to be refunded within 14 days.
He also paid tribute to his team’s "heroic" efforts during the crisis.
“I am very proud of everyone in the team at Vivid Travel," said Pirie. "They have been truly heroic in this extraordinary year."