Loveholidays has followed On the Beach in resigning its Abta membership.
The OTA has cited "divergent views" on its and Abta’s stance on the legal position around cancellations and refunds.
It comes just two days after fellow OTA, On the Beach, resigned its Abta membership over similar concerns.
"The Covid-19 pandemic has caused unprecedented challenges for holidaymakers, which have been exacerbated by frequent changes in travel guidance issued by the UK government," said a loveholidays spokesperson.
"The current package travel legislation was never designed to deal with disruption on the scale we have seen since March 2020. Unfortunately, as a result of our divergent views on the legal position regarding cancellations and refunds, we have decided that it is no longer possible for loveholidays to remain a member of Abta."
They added: "We would like to reassure all our customers that package holidays booked with loveholidays remain financially protected by the ‘gold standard’ Atol scheme.
"We believe the priority for everyone in the travel industry should be to come up with a workable, fair solution to help holidaymakers get their money back as quickly as possible.
"Speeding up the refund process for airlines must be a key part of this solution, and we urge the entire industry to focus on working together to make this possible."
An Abta spokesperson said: "Loveholidays has chosen to resign from Abta membership following ongoing discussions about refunds due to customers when the Foreign Office advice changes to advise against all, or all but essential travel to a destination.
"Abta is firm in its position that the longstanding practice of offering a full refund when the Foreign Office advises against travel still stands."