Passengers onboard MSC Virtuosa have been told they will not be allowed to disembark in Scotland under Covid-19 regulations.
Operator MSC Cruises said Scottish government rules block it from entering the port of Greenock.
The government has said domestic cruises can only restart when restrictions in all of Scotland reach level one.
It insisted the decision was based on the risks “between both cruises and the wider travel context”.
The MSC Virtuosa left Liverpool earlier this week for a seven-night cruise, with planned stops in Greenock in Inverclyde, as well as Belfast, Southampton and the Isle of Portland.
MSC Virtuosa was then due to stop in Greenock again on the return journey.
The vessel can carry more than 6,000 passengers but has just under 900 currently on board to allow for social-distancing measures.
The ship had been expected to arrive at approximately 09:30 this morning and depart the port again at 20:00.
The ship had also been expected on June 16th and 23rd, with those embarkations also not likely to be cancelled.
Joanne Dooey, president of the Scottish Passenger Agents’ Association (SPAA), said: “We are now facing the situation where Scottish passengers who joined the cruise in Liverpool are barred from setting foot in their own country.
“The SPAA has been asking for clarity on the situation for this particular cruise ship since last week, and all we have received so far is an indicated that cruises may only restart when all of Scotland is in level one.”
Passengers booked to embark on future MSC Cruises at Greenock may face being transported by road to Liverpool to be permitted to join the vessel.