The transport secretary is facing calls to quit after it was revealed £33m in taxpayers' money was paid to Eurotunnel over controversial no-deal Brexit ferry contracts.
Chris Grayling is under pressure to resign over the move , which is the latest in a list of mishaps he has overseen.
In exchange for the cash, Eurotunnel dropped legal action brought against the "secretive" process used around the shipping deals.
They were struck to ensure the flow of critical supplies if Britain leaves the EU without an agreement on 29 March.
The Channel Tunnel operator had challenged the Department for Transport's decision to award contracts worth £108m to three ferry companies at the High Court.
One of the firms was Seaborne Freight, which sparked a storm of criticism as it did not have any ships and appeared to have copied its terms and conditions from a takeaway website.
The deal was subsequently scrapped by Mr Grayling last month after its financial backer Arklow Shipping pulled out.
Commenting on the £33m payout, Labour's shadow transport secretary Andy McDonald said: "What does it take for this secretary of state to be sacked?
"He stumbles from catastrophe to disaster and it's just gross incompetence on an industrial scale.
"Enough is enough and this man has got to be out of his post by Monday."
Angela Smith, The Independent Group's transport spokesperson, said the £33m "could have been put to much better use".
"This really is the last straw - time for Grayling to go," she wrote on Twitter.
In response, Downing Street has insisted Prime Minister Theresa May has "full confidence" in Mr Grayling.
Her spokesperson said: "We took the decision to come to an out-of-court agreement to ensure that [the supply of] vital goods would not be put into jeopardy in a no-deal scenario.
"Our view is that a court case would have put at risk that extra vital freight capacity that we have secured already.
"Settling allows us to concentrate on the job at hand of continuing with our no-deal contingency planning."
They stressed the settlement was "absolutely not" an attempt to keep details of the saga out of the public domain.