P&O Ferries’ Pride of Hull will not return to service until the end of the month, the company has said.
The vessel is docked in Rotterdam after sailing from Hull following P&O’s decision to sack 800 workers in favour of lower-paid replacements.
It was expected to restart its nightly North Sea crossing on 4 April, but in a tweet the ferry firm said it hoped to “resume service from the 23rd April”.
Sister ship Pride of Rotterdam began sailing again last week.
The BBC has contacted P&O for an update on the Pride of Hull.
It was cleared to sail with passengers and cargo after passing an inspection by the UK’s Maritime and Coastguard Agency (MCA).
The Pride of Hull, which is classed as a foreign vessel, is registered in the Bahamas. Countries where ships are flagged bear overall responsibility for their safety, the MCA said.
Responding on Twitter to a customer asking about a booking in May, the company said “If your booking is affected we will be in contact with you directly. We apologise for the inconvenience and uncertainty at this time”.
The Pride of Hull crew occupied the ship for five hours after the sackings were announced
More than 80 crew members in Hull were sacked without warning by P&O in a video call on 17 March.
The firings triggered a sit-in by the Pride of Hull crew who occupied the vessel in the city’s King George Dock for more than five hours.
Protests were also held at the quayside.
P&O Ferries claimed that without the redundancies the business was “not sustainable” after losing £100m last year.