Marella Cruises has extended its suspension of operations until 30 September.
The line has also confirmed only Marella Explorer will sail this summer – homeporting out of Corfu from 2 October.
Customers with impacted bookings will receive a refund credit and an extra incentive of up to 10% of the total value of their booking, or they can request a cash refund using an online form on the Tui website.
Customers with bookings due to depart in October can amend their cruise for free before 31 July to any other holiday on sale until October 2021.