Shadow Environment Secretary Jim McMahon slammed P&O Ferries on GB News after 800 seafarers were sacked from the company.
The 800 workers were sacked immediately, with no notice, so they can be replaced by cheaper labour.
Mr McMahon said: "I think the way P&O have behaved is a national disgrace. It's an absolute scandal that 800 people were told that they would be sacked on the same day by a video call.
"This is the company that reflagged away from Britain to Cyprus after the EU referendum.
"This is the same company that took millions in furlough only to make 1100 people redundant, at the same time paying over £200million in shareholder dividends.
"It's the same company that today are making a £1billion pound of profit and saying they need now to make these 800 hard-workers redundant.
McMahon spoke to Stephen Dixon and Beverley Turner on GB New's Breakfast programme
GB News
"These are 800 people who have bills to pay and families to support. Whole communities depend on that industry and frankly, it's a national scandal that has been allowed to happen on the Government's watch."
GB News' Stephen Dixon highlighted the UK Government's condemnation of P&O's dismissal of the workers, after Transport Minister Robert Courts said the company’s actions were “wholly unacceptable".
Mr McMahon told GB News: "We've asked the Government to get legal advice to find out whether it was even lawful to make these people redundant in the way that we saw on TV."
Former P&O staff members collect belongings at the Port of Dover as P&O Ferries suspended sailings and handed 800 seafarers immediate severance notices, saying: "Our survival is dependent on making swift and significant changes." Picture date: Thursday March 17, 2022.
Gareth Fuller
Travel journalist, Simon Calder, emphasised to GB News that many P&O workers could be on contracts based in Jersey, which are covered by maritime law and not UK law.
The Shadow Environment Secretary said: "The treatment of seafarers who are UK citizens is an issue and it's been a long-standing problem that depending on where the ship is flagged, depending on when the company is registered, that does diminish workers rights here in the UK."
GB News asked Mr McMahon how Labour would ensure an incident like this did not occur again in the future.
The MP for Oldham West and Royton said: "People at the moment feel as though they're being exploited.
"We need to make sure that we toughen-up our employment laws here in the UK.
"If you are a UK citizen working here and your base is here, you deserve better terms and conditions and better rights than if your company is offshore."