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.