Senior Cabinet ministers have rounded on Airbus and other firms after they questioned the Government's handling of Brexit negotiations.
Jeremy Hunt accused them of making "completely inappropriate" threats, warning that undermining Theresa May could lead to a disastrous "fudge".
Liam Fox warned that taking "no deal" off the table during Brussels negotiations would weaken the UK's bargaining position.
Their comments came after Airbus, Siemens and BMW all raised concerns about the direction of travel in negotiations and urged the Government to provide greater clarity.
Health and Social Care Secretary Mr Hunt said the country needed to ignore "siren voices", telling the BBC's Andrew Marr Show: "I thought it was completely inappropriate for businesses to be making these kinds of threats for one very simple reason.
"We are at an absolutely critical moment in the Brexit discussions and what that means is that we need to get behind Theresa May to deliver the best possible Brexit - a clean Brexit.
"What businesses want... is clarity and certainty and the more that we undermine Theresa May the more likely we are to end up with a fudge, which would be an absolute disaster for everyone."
Airbus, which employed 14,000 people in Britain, threatened to quit the UK in the event of a no-deal Brexit and demanded that any transition period if a deal is struck be longer than that currently proposed, which ends in 2020.
Ian Robertson, BMW's special representative in the UK, told the BBC uncertainty was causing problems for the industry.
The German carmaker employs around 8,000 people in the UK, with its plant in Oxford producing the popular Mini range.
And Siemens UK chief executive Juergen Maier on Saturday branded some of the political rhetoric "unhelpful" and all three firms urged the Government to give greater clarity over its plans as quickly as possible to allow them to make business decisions.
However, Theresa May has also been urged by hardline Brexiteers to speed up preparations for a "no-deal" Brexit to put pressure on Brussels during withdrawal negotiations.
Former chancellor Lord Lawson, ex-environment secretary Owen Paterson, Wetherspoon boss Tim Martin and Sir Rocco Forte were among signatories of a letter to the Prime Minister urging her to issue orders to departments to accelerate planning for Britain to operate under World Trade Organisation (WTO) rules if a deal cannot be done.
They argue that in order to have "real leverage in the Brexit endgame" the UK must reserve the right to walk away without a trade deal "and take with it the GBP39 billion it has offered to pay as part of a divorce settlement".
Dr Fox, the International Trade Secretary, told Sky News' Sophy Ridge On Sunday that the businesses should also be raising their concerns to figures in Brussels.
He said: "If we actually say we'll accept any deal you give us rather than walk away, that weakens our negotiating position.
"And people who are making these comments need to understand that they may be actually putting the UK at a disadvantage by making these cases.
"We've got to be free in the negotiation to say if we don't get the deal we want, there won't be any agreement."
Dr Fox added that extending Article 50, which governs when the UK leaves the EU would not be politically acceptable.
But he said he would not have a major objection if the transition period was extended, as long as it was time limited and for technical reasons.
There would also need to be a mechanism for the UK to walk away "if we thought that we were being kept in the European Union against our will", he added.
Lib Dem Brexit spokesman Tom Brake criticised Mr Hunt, saying his comments seemed "calibrated more to appeal to his Brexiteer colleagues than to reflect reality".
He added: "The Conservatives are making a mess out of Brexit, and businesses are right to raise concerns and spell out what decisions they may take in reaction to a botched deal.
"Whilst the Conservatives may wish to ignore reality and pat each other on the back after two years of achieving precisely nothing in the Brexit negotiations, they cannot expect businesses to act in the same way."