Services between Dover and Calais will temporarily not go ahead.
Some reports state this is down to an operational “incident” and a big announcement is set to come today.
Posting on Twitter, the company wrote: “Regretfully, P&O Ferries services are unable to run for the next few hours. Our Port Teams will guide you and travel will be arranged via an alternative operator.
“We apologise for the inconvenience this will have on your journey plans.”
P&O added there is set to be a company announcement.
“P&O Ferries is not going into liquidation. We have asked all ships to come alongside, in preparation for a company announcement,” a P&O spokesperson stated.
“Until then, services from P&O will not be running and we are advising travellers of alternative arrangements.”
The travel suspension is predicted to last a few hours, according to P&O.
A statement released by the company to staff reads: “We will be making a major company announcement today which, with the support of our shareholder DP World, will secure the long-term viability of P&O Ferries.
“To facilitate this announcement all our vessels have been asked to discharge their passengers and cargo and standby for further instructions.
“That means we’re expecting all our ports to experience serious disruption today so please bear with us and we will give further information in an all-colleague announcement later today.
“If you’re in a customer-facing role further information with follow separately on how we would like you to work with our customers. Thank you for your patience and support.”
Those who have bookings have been urged to look for alternative modes of transport.
This may include using P&O competitors or the Eurotunnel, for those heading to Europe.
The company advised headling to port to make alternate arrangements.
P&O Ferries listed a number of cancellations on it’s Twitter page.
Services running to Calais, Larne, Cairnryan and Dover are likely to be affected.
Further updates will be given by text and on social media.
P&O Ferries Twitter page added: “Please arrive at the port as booked and we will arrange to get you away on an alternative carrier as quickly as possible.
“Once at the port please make your way to the DFDS check-in booths.”
P&O Ferries is a popular option for those travelling abroad.
The operator runs services from the UK across Europe.
Britons can set sail to Ireland as well as France, Belgium and the Netherlands.
Those with bookings headed to Twitter to share their concerns with the cancellations.
“But who is going to let us know and when please? We were meant to be on the 6:30 ferry, sat here since 5:30 and not one person has explained anything?” Twitter user Beckie McLaughlan questioned.
P&O Ferries Updates replied: “You will be sailing with DFDS. My colleague will be coming over soon.
“Please hang tight. I’m very sorry about this.”
Another user stated they were struggling to use the other services suggested.