Thomas Cook has announced it is planning to close a further 21 stores, placing 320 retail roles at risk.
More than 100 customer-facing roles will be made redundant, with Cook proposing to remove another 218 store-based roles.
A consultation process with affected staff and union representatives is under way.
In total, 102 roles will be made redundant - 3.5% of Cook’s retail workforce - rising to 8% with the addition of the other 218 jobs.
Will Waggott, Cook chief of tour operating, said: “Today’s announcement reflects the wider challenges seen on the high street, with more and more customers choosing to book online.
“These measures will help us to drive greater efficiencies across Thomas Cook so that we relentlessly focus our resources in those areas that give us the greatest opportunity to make a difference to customers in our core holiday offering.
“Looking ahead, we will be working to ensure that Thomas Cook is fit for the future, putting a rigorous focus on costs in a competitive environment while giving customers more reasons to holiday with the strongest brand in travel.”
The move is part of Cook’s ongoing review of its entire UK business, which includes addressing the performance of its UK tour operation.
It also sits alongside a review of its group-airline, comprising Thomas Cook Airlines in the UK and Condor in Germany, as well as its Belgian and Scandinavian divisions.
Cook said “streamlining” its UK retail network, which once comprised more than 1,200 stores, would allow it to drive greater efficiencies across the business amid changing customer behaviour.
Some 64% of all Cook bookings in the UK last year were made online, now the business’s fastest growing sales channel - up 30% last year.
The latest closures will cut Cook’s retail network to 566 shops. A Cook spokesperson confirmed the majority of the affected stores were approaching the end of their lease.