Ferry company Stena Line has announced it plans to make 150 redundancies and furlough 600 employees across Ireland and the UK.
The Swedish-owned firm says this is "an unavoidable response" due to the on-going global COVID-19 crisis.
It says the pandemic has had a "hugely damaging effect" on travel and transport across Europe.
However the company adds that workers who are furloughed will maintain 80% of their salaries.
Where Irish and UK government schemes do not cover the full amount, the remainder will be paid by the firm.
Stena Line says it has experienced "a large decline in travel bookings and freight volumes" since the crisis emerged.
It is estimated that passenger figures will not recover until well into 2021.
As a result, it says it is forced to take "tough decisions" in order to cut costs and ensure that vital supply lines of essential goods to Ireland and the UK are protected.
Ian Hampton is director at Stena Line.
He says: "The COVID-19 crisis has meant that Stena Line is experiencing a significant decline in passenger and freight volumes across all its 20 European routes
"We are having to make some very difficult decisions, that we hoped we would never have to make."
The announcement of furlough and redundancies relates to both Ireland and UK shored-based and sea-based employees - including those working on vessels on the Irish Sea and North Sea.
It follows a reduction of the number of sailings on several routes - while a number of vessels have also been taken out of service.
Mr Hampton adds: "In order to secure the continuity of our freight operations, we have no choice but to reduce our costs.
We are committed to keep vital supply lines open for UK and Ireland.
"Regrettably we must furlough employees on temporary paid leave and make redundancies, as we adjust to this new reality."
Stena Line says it is planning for the long-term, with a consultation on furlough and redundancies with trade unions due to begin on Monday.
Last month, Stena Line also announced redundancies that will affect 950 people employed in Scandinavia.
A number of these employees have since been furloughed - while further job losses have been made in Denmark and the Baltics.