P&O Ferries is permanently shedding 1,100 jobs to "right-size" the business during the coronavirus crisis.
The UK-based company said it had no choice after running a reduced number of vessels. The figure represents more than a quarter of its workforce.
Its Dubai owner, shipping and ports group DP World, had previously said the ferry business needed £275m ($329m) to avoid collapse.
And in April, DP World chief executive Sultan Ahmed bin Sulayem told the BBC the company had applied to the UK government for £150m.
P&O will lay off 614 staff on the Dover to Calais crossing, and another 122 people between Hull and Zeebrugge and Rotterdam.
The rest of the redundancies will involve officers and shore staff linked to the same routes.
Mick Cash, general secretary of the RMT union, criticised the move, saying: "This is an attack on British seafarers and crew, and the biggest fear is that these jobs will never return to Dover or Hull."
P&O said a consultation period was now under way.
The company has already furloughed about 1,400 staff in the crisis.
The ferry operator has also received UK government assistance through a freight scheme announced in April, but the amount has not been revealed.
Creating a viable company
"Since the beginning of the crisis, P&O Ferries has been working with its stakeholders to address the impact of the loss of the passenger business," the company said.
"It is now clear that right-sizing the business is necessary to create a viable and sustainable P&O Ferries to get through Covid-19."
That right-sizing means a cut in the operating fleet.
"Regrettably, therefore, due to the reduced number of vessels we are operating and the ongoing downturn in business, we are beginning consultation proceedings with a proposal to make around 1,100 of our colleagues redundant," the company said.
DP World said in March it was paying out £270m to investors as dividends.
The state-controlled company told The Guardian that the payout related to its de-listing from the Nasdaq exchange in Dubai.
The move is a legal requirement and pre-dates the pandemic, DP World added.
