Tui has postponed the launch of its river cruise fleet and cancelled all sailings until after 2 May.
The travel giant was due to debut its new river ships at an event in Amsterdam on 23-25 March.
The first public sailings were due to depart on 29 March with itineraries on a number of European waterways.
Customers booked on to departures up to and including 2 May will receive a full refund or can rebook onto any other available sailing until 31 October.
Those who choose to amend to a later sailing, and the new cruise is more expensive, the difference in cost will be covered and if it costs less than the original booking they will be refunded the difference.
“We are contacting customers directly, prioritising those with the most immediate sailings. We are asking people not to ring the call centre and for anyone with a later April booking to be patient,” a Tui spokesperson said.
“We have been working hard for the past year to get our three ships river-worthy and to welcome our first guests onboard, so of course this is disappointing. But in the current unprecedented situation we know our customers will understand and support this decision,” she added.