P&O Ferries has announced plans to make 1,100 of its staff redundant.
The ferry operator, based in Dover, Kent, said the reduced number of vessels and downturn in business had forced its decision to lay off staff.
A spokesperson for the firm said “right-sizing” the business was a necessary step to create a viable and sustainable P&O Ferries.
The owners of P&O Ferries had previously stated the business needed £257m in aid to avoid collapse.
Natalie Elphicke, MP for Dover and Deal, said the news was “disappointing” and urged P&O’s owners to “stump up or sell to better owners”.
She said: “Let’s remember that P&O, which is owned by the Sovereign State of Dubai, has received millions of pounds of financial support from our government in recent weeks. There can be no doubt that Dubai has more than enough money to keep P&O going in full.
“It cannot be right for them to have taken millions of pounds from the hard-working British taxpayer in furlough and freight support payments and then decide to pull the rug.”
In April, Sultan Ahmed bin Sulayem told the BBC the company had applied to the UK government for £150m.
P&O Ferries is now working towards making 614 staff on the Dover to Calais line redundant, with a further 122 job losses on the lines between Hull and Zeebrugge and Rotterdam. The remainder are officers and shore-side staff on the same routes.
Mick Cash, general secretary of the RMT union, said it was “utterly shameful” P&O was kept afloat by the taxpayer.
He said: “This is an attack on British seafarers and crew, and the biggest fear is that these jobs will never return to Dover or Hull.
“But you can guarantee that P&O ferries will still be running passenger ferry services from those ports to protect their owner’s profits at the country’s expense.”
P&O said a consultation period was now under way.
It said: “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.
“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.”