Stena Line are set to operate additional ferries from Northern Ireland to Scotland to combat the impact of P&O Ferries suspending services.
UK Transport Secretary Grant Shapps confirmed the extra sailings will take place from Tuesday, March 22, and will help retailers such as Marks and Spencer and Asda.
He said the company had already "stepped up" following the suspension of P&O routes last week.
Read more: P&O workers at Larne Harbour living a 'bad dream' after shock redundancies
Sailings between Larne and Cairnryan have been cancelled for days and protests have taken place after P&O Ferries sacked 800 staff members and suspended all of its services on Thursday, March 17.
Up to 50 staff from Northern Ireland will be directly impacted by the move, which saw workers replaced by agency staff with no notice.
Mr Shapps said if it was confirmed that relative notice periods and consultations were not conducted before P&O staff were fired, then it would be a "a matter for criminal prosecution and unlimited fines".
The Economy Minister Gordon Lyons has accused the firm of "ripping up the employment rule book".
Mr Lyons said he did not believe P&O had acted within either the "spirit or letter" of employment law, a matter devolved to Northern Ireland.
The company sacked 800 members of staff on Thursday, March 17, with a quarter of workers hearing the message via a pre-recorded message.
Stunned workers in Larne were escorted off their vessel, the European Causeway, by security wearing balaclavas and armed with handcuffs, they alleged.
Workers staged a protest at the P&O terminal in Larne Port on Friday afternoon, and spoke out following their ordeal.
Daniel McDonald, 45, had been working at P&O Ferries for 17 years and was onboard the European Causeway docked in Larne on Thursday morning when staff were told the news.
He told Belfast Live: "They read out a statement saying P&O was losing money and that all Jersey P&O contracts were being terminated as soon as possible. We had two hours to gather our belongings then would be escorted off the vessel.
"I couldn't get to say cheerio to some of my co-workers I've worked with for 17 years, I was escorted up to my cabin where I collected personal belongings. I walked off with my suitcase and carrier bags, things falling out, and they just stood and watched me.
"I walked to the top of the ramp and handed over my pass and they gave me an envelope, there was a bus sitting there with crew waiting to come on and take our jobs. So our jobs are still there, they've just been given to different people."
Read more: P&O issues statement in wake of outcry over mass redundancies
Read more: P&O Ferries issues statement amid ongoing delays at ports
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