Health Secretary Jeremy Hunt has acknowledged that "threats" by enterprise over Brexit are "completely inappropriate".
He was responding to warnings by Airbus and BMW that investments within the UK might be jeopardised by Brexit uncertainty.
Speaking on The Andrew Marr Show, Mr Hunt mentioned Brexit discussions had been at "critical moment" and wanted unity.
Last week, Airbus warned it may depart if the UK exits the one market and customs union with no transition deal.
BMW adopted the warning from Airbus by saying that readability over Brexit is required by the tip of the summer time.
In response Mr Hunt mentioned: "It's fully inappropriate for companies to be making these sorts of threats.
"We are in 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."
BMW makes the Mini and Rolls Royce and employs about eight,000 individuals within the UK.
BMW UK boss Ian Robertson mentioned he wanted to know inside months what the federal government's most well-liked place was on customs and commerce publish Brexit.
"If we don't get clarity in the next couple of months we have to start making those contingency plans... which means making the UK less competitive than it is in a very competitive world right now," he mentioned.
"That is a decisive issue that ultimately could damage this industry."
BMW has constructed up an various manufacturing base within the Netherlands amid considerations about Britain's suitability as an export hub after Brexit.
The customs union brings collectively the EU's 28 members in a duty-free space, wherein they pay the identical fee of obligation on non-EU items.
Prime Minister Theresa May has dominated out staying within the customs union after the UK leaves the EU on 29 March 2019.
Airbus, in its Brexit "risk assessment" revealed on Thursday, mentioned if the UK left the EU subsequent 12 months with out a dealleaving each the one market and customs union instantly with none agreed transitionit could "lead to severe disruption and interruption of UK production".
The European plane-maker mentioned the warning was not a part of "Project Fear", however was a "dawning reality".
The time period "Project Fear" has been utilized by some pro-Brexit campaigners to indicate alleged scaremongering by these in favour of remaining within the EU.
The former director-general of the British Chambers of Commerce, John Longworth, who co-chairs Leave Means Leave, mentioned Airbus had given related warnings years in the past.
"They've also stated that they're quite prepared to move production to places like China, which is not even in the European Union," he advised the BBC.
"So how can that possibly be anything to do with Brexit?"
Airbus's 14,000 UK employees are employed throughout 25 manufacturing websites. About half are in Wales.
The firm, which makes wings for the A320, A330/A340, A350 and A380 passenger planes within the UK, additionally mentioned the present deliberate transition interval, as a result of finish in December 2020, was too brief for it to make modifications to its provide chain.
As a consequence, it could "refrain from extending" its UK provider base. It mentioned it presently had greater than four,000 suppliers within the UK.
Between 2012 and 2015, BMW Group invested £750m to improve manufacturing websites in Oxford, Hams Hall and Swindon.
The firm additionally has its Goodwood manufacturing plant in West Suss3x, a UK gross sales and advertising subsidiary in Farnborough and a automobile distribution centre in Thorne.