P&O Ferries has suspended sailings after announcing it was making staff redundant to save the operation as a going concern.
The 800 workers will be dismissed on terms in an attempt to stem losses, which were about £100 million ($131 million) last year.
P&O, which said earlier on Thursday that it would be unable to operate services for the next few days, said its survival was dependent on making swift and significant changes immediately.
"Without these changes there is no future for P&O Ferries," a P&O representative said.
P&O Ferries operates four routes: Dover to Calais; Hull to Rotterdam; Liverpool to Dublin; and Cairnryan, Scotland, to Larne, Northern Ireland.
Sailings between Hull and Zeebrugge, Belgium, were discontinued in January 2021.
A spokesperson for P&O Ferries said the company was currently not a “viable business” and 800 seafarers had been handed immediate severance notices with compensation packages for the “lack of advance notice”.
The firm said: “P&O Ferries plays a critical role in keeping trade flowing, supply chains moving, and connecting families and friends across the North and Irish seas and the English Channel. We have been at the heart of this service for years and we are committed to serving these vital routes.
“However, in its current state, P&O Ferries is not a viable business. We have made a £100m loss year on year, which has been covered by our parent DP World. This is not sustainable. Our survival is dependent on making swift and significant changes now. Without these changes there is no future for P&O Ferries.
“These circumstances have resulted in a very difficult but necessary decision, which was only taken after seriously considering all the available options. As part of the process we are starting today, we are providing 800 seafarers with immediate severance notices and will be compensating them for this lack of advance notice with enhanced compensation packages.
“In making this tough decision, we are securing the future viability of our business which employs an additional 2,200 people and supports billions in trade in and out of the UK. And we are ensuring that we can continue serving our customers in a way that they have demanded from us for many years.”
Britain's Transport Secretary Grant Shapps told the House of Commons he is “concerned” by the situation.
He said: “I understand they have temporarily paused their operations and that’s causing disruption at the short straits – Calais-Dover – as well as some other ports.
“I’m working with the Kent Resilience Forum and I’ve just instructed them to become intricately involved, and other partners in this, and we’ll be taking steps later today – including ensuring that my officials will be having urgent discussions with P&O about the situation, particularly of concern for their workers.”
After the coronavirus outbreak, P&O Ferries said in May 2020 that about 1,100 workers could lose their jobs as part of a plan to make the business “viable and sustainable”.
The company that would become P&O Ferries was founded in 1837 after signing a government contract to transport post by boat between London and the Iberian Peninsula.
