Irish Ferries is to compete on the Dover-Calais route from the summer.
The company plans to challenge established ferry operators on the short sea route between the UK and France from June.
The ship Isle of Inishmore is to be transferred to the route with additional capacity added.
Irish Ferries is chartering passenger ferry Blue Star 1 for the Rosslare-Pembroke route from April ahead of Isle of Inishmore moving.
While mainly targeted at hauliers, passenger services will be offered on the Dover-Calais route.
“The initial level of passenger services offered will be dependent on the easing of Covid-19 travel restrictions,” Irish Ferries said.
A company spokesperson added: “We are very excited about launching our services on the best short sea ferry market in the world and we believe we can bring more choice for customers in the years ahead.
“As part of our commitment to the movement of freight on and off the island of Ireland to both the UK and Europe, this additional capacity on the Dover-Calais route will significantly strengthen the capacity and reliability of the landbridge for exporters and importers.
“Hauliers will now have one operator providing an inclusive service on the Dublin-Holyhead, Rosslare-Pembroke and Dover-Calais routes. This will allow exporters and importers easier, cheaper, and quicker access to our European markets via the Common Transit Convention.
Irish Ferries managing director Andrew Sheen said: “We are very pleased to add a quality ship of the calibre of the versatile Blue Star 1 to the Irish Ferries fleet.
“This ship will be the fastest ro-ro passenger ship operating between Britain and Ireland and this will help ensure schedule integrity.
“The introduction of this ship underlines our commitment to the Rosslare to Pembroke route, the primary shipping corridor between Ireland and South Wales.”
Port of Dover chief executive Doug Bannister said: “This announcement gives the millions of customers across the UK and the Republic of Ireland who value the intrinsic benefits of the shortest sea crossing to Europe, the prospect of even more choice.
“We believe the inclusive landbridge product will be popular with Irish exporters and will strengthen the just in time supply chain into the European Union.
“This is a clear signal of market confidence in the Dover route and will complement the resilient services currently provided.”