The Prime Minister said it appears to him that P&O Ferries has “broken the law” over the controversial sacking of 800 workers.
He told the Commons that the Government will be “taking action”, and encouraged workers to do the same.
His statement came as the company’s chief executive issued an apology for the impact of the decision to sack the staff without notice.
Peter Hebblethwaite said he understood the “anger and shock” about the loss of jobs.
His statement came amid continued protests by unions and workers and followed confirmation that he will appear before MPs on Thursday to be questioned about the dismissals.
There is anger and shock and I completely understand.
He said: “I want to say sorry to the people affected and their families for the impact it’s had on them, and also to the 2,200 people who still work for P&O and will have been asked a lot of difficult questions about this.
“Over the last week, I’ve been speaking face-to-face to seafarers and their partners. They’ve lost their jobs and there is anger and shock and I completely understand.
“We needed fundamental change to make us viable. This was an incredibly difficult decision that we wrestled with but once we knew it was the only way to save the business, we had to act.
“All other routes led to the closure of P&O Ferries. I wish there was another way and I’m sorry.”
Mr Hebblethwaite will appear before a joint hearing of the Transport and Business, Energy and Industrial Strategy committees on Thursday.
Protests were held in Dover and Liverpool on Wednesday against the sackings, which have been widely condemned by union leaders and politicians.
Other witnesses being questioned on Thursday will include Professor Alan Bogg, Professor of Labour Law at University of Bristol, Mark Dickinson, general secretary of Nautilus International, Dean Beale, chief executive of the Insolvency Service, Brian Johnson, chief executive of the Maritime and Coastguard Agency, Katy Ware, director of UK Maritime Services, transport minister Robert Courts and business minister Paul Scully.
Huw Merriman and Darren Jones, who chair the committees, said: “This session will aim to understand the detail of the options available to the 800 workers who were roundly dismissed by P&O Ferries last week.
“The cruel nature of their dismissal put employment practices and UK plc under the microscope.
“From P&O Ferries, our members want to know why this action has been taken and how it can be justified.
“From the Government and its agencies, we want confirmation that our laws are not being broken and safety is not being compromised on our ships.
“This shocking story has raised questions about UK employment law, safety practices, the support of this business through a pandemic and the redress available. We intend to hear from the key players about what they are going to do that means these workers are not left high and dry.”
