Transport Secretary Grant Shapps said the chief executive of P&O Ferries should resign after his "brazen" and "breathtaking" comments about "knowingly breaking the law".
It comes after chief executive Peter Hebblethwaite admitted the company broke employment law when it sacked 800 workers without notice.
The Transport Secretary told Sky News: "I thought what the boss of P&O said yesterday about knowingly breaking the law was brazen and breathtaking, and showed incredible arrogance.
Read more: P&O admits breaking law over sackings
"I cannot believe that he can stay in that role having admitted to deliberately go out and use a loophole - well, break the law, but also use a loophole."
Pressed on whether that meant he was calling for Mr Hebblethwaite to resign "right now", he said: "Yes."
He added the Government is planning to change the law to ensure companies working from British ports pay people the minimum wage.
It comes after Mr Hebblethwaite said new P&O crews are being paid below the UK's minimum wage apart from on domestic routes, but insisted this is allowed under international maritime rules.
"What I'm going to do ... is come to Parliament this coming week with a package of measures which will both close every possible loophole that exists and force them to U-turn on this," Mr Shapps said.
"We are not having people working from British ports ... plying regular routes between here and France or here and Holland, or (anywhere) else, and failing to pay the minimum wage. It's simply unacceptable and we will force that to change."
Asked if the Government will change the law to enforce this, he said: "That's exactly the plan."
The ferry operator, bought by Dubai-based logistics giant DP World in 2019, has insisted the decision to cut jobs was “very difficult but necessary” as it was “not a viable business” in its current state.
Read more: P&O issues statement in wake of outcry over mass redundancies
Read more: P&O workers at Larne Harbour living a 'bad dream' after shock redundancies
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