Marella Cruises has extended its pause in cruise operations through to the end of June.
The line confirmed the decision on Thursday (11 March), which applies to all cruises due to depart up to, and on, 30 June.
"Due to the ongoing uncertainty around travel restrictions, Marella Cruises has extended its pause in operations up to and including 30 June 2021," said Marella.
"We’re proactively contacting impacted customers from 11 March to discuss their options, which will include amending to another holiday for free with an incentive or cancelling and receiving a full refund."
Several lines, including Princess Cruises, P&O Cruises and Cunard, have already axed their European summer schedules.
All three, most recently Cunard on Thursday (11 March), now plan to operate a range of summer "staycation" cruises in UK waters after the UK government confirmed efforts to restart domestic cruising would be determined alongside plans to restart domestic land travel.