Around 450 jobs are to be axed by Carnival UK which operates cruise lines P&O Cruises and Cunard amid the coronavirus pandemic.
The company said it wants to treat everyone "with fairness and respect" but said the changes were needed to "ensure the future sustainability" of the business.
The news comes after P&O Ferries said yesterday it would be forced to cull a quarter of its employees by making them redundant, as the pandemic continues to have a major impact on businesses.
PA reports a Carnival UK spokesman said: "We have begun a period of consultation with our staff in Southampton across all levels of the business.
"Our priority is to treat everyone with fairness and respect and to have open and honest conversations.
"These changes, whilst very difficult, are to ensure the future sustainability of our business.
"The Covid-19 pandemic has not only affected the holidays of our guests but it has also impacted every part of our business: our future deployment, the guest experience, our supply chain and our people on ship and on shore.
"During our pause in operations we have tried to create as much certainty and stability as possible for our staff in Southampton and crew on board our ships.
"Unfortunately though and like many businesses, as Covid-19 has continued to impact our way of life, it is necessary to make changes to our organisation to build a stable platform for the time we phase our ships back into service and for future growth."
Carnival is based in Southampton and owns the historic P&O Cruises and Cunard lines, which employ around 1,100 people in the Southampton and Hampshire area.
