Saga Cruises has postponed its planned return to service until later in 2021.
Spirit of Discovery will not resume cruises until April instead of March.
The introduction of new ship Spirit of Adventure has been delayed from February until May 4.
The confirmation came in a message to customers by managing director Nigel Banks.
The latest extension of the suspension of cruises comes against the backdrop of the Covid-19 second wave and restrictions on cruise ships around the world.
“We have sadly seen the predicted restrictions on day-to-day life increasing,” Blanks said.
“This has led us to further review our planned dates for a return to service, as the seasonal impact of Covid-19 would indicate that we are unlikely to be able to cruise in February on Spirit of Adventure, or March on Spirit of Discovery.
“I would therefore like to confirm that, following careful consideration, we have taken the very difficult decision to postpone our return to service for Spirit of Discovery until April 2021 and Spirit of Adventure’s inaugural cruise has also been rescheduled and she will now sail for the first time on May 4, 2021.
“This means that all cruises up to these dates will no longer operate and your cruise will not be going ahead as planned.
“Whilst I know that this news will be disappointing, I also know that you will understand our reasoning and appreciate us making this decision sooner rather than later.”
The company will continue to review its Covid-19 protocols and arrangements on a regular basis, Blanks added.