A city business group has warned "political point-scoring" could jeopardise the reopening of Doncaster Sheffield Airport (DSA).
The Doncaster Chamber has urged politicians to show a united front.
It comes after South Yorkshire's mayor accused the government of rejecting a request to reallocate £30m of funding.
The Department for Transport (DfT) said Oliver Coppard's letter had not constituted a formal request and had therefore not been treated as such.
Mr Coppard said he had written to Transport Secretary Mark Harper in December asking to repurpose the money for the reopening of the airport, which was shut 18 months ago.
The £30m had initially been earmarked for a new rail link to DSA as part of City Region Sustainable Transport Settlements (CRSTS) funding.
In his correspondence to Mr Harper in December, Mr Coppard said DfT officials had "indicated that they do not support a reallocation of funding to other airport capital costs, on the grounds that they are not consistent with CRSTS objectives or deliverable."
"I am therefore writing to formally ask you to reconsider that decision," he added.
The DfT said no formal request or business case had been submitted by the South Yorkshire Mayoral Combined Authority therefore no review had taken place.
MP for Don Valley, Nick Fletcher, said he had been at the "forefront" of the campaign to keep DSA open and agreed with the Chamber, adding: "A grown-up approach is needed."
He accused Mr Coppard of "ignoring procedures when it suits you" and said: "If he spent less time criticising the government and more time doing his job, maybe these sort of things wouldn't happen."
Mr Coppard said he considered his letter "a sufficiently formal request".
Writing on X, he said the DfT had previously said the money could not be used to reopen DSA and questioned whether this would change had the request been made "more formally".
Doncaster Chamber Chief Executive Dan Fell issued a plea for unity.
He said: "Unfortunately, we are seeing a lot of unwelcome commentary at the moment that, at best, is a needless distraction and, at worst, could potentially jeopardise the future of this hard-fought campaign by spooking potential investors.
"The negotiations here are necessarily detailed and complex and we need to give those in the thick of it time and space to get it over the line. 24/7 commentary is not going to be conducive to that goal."
Mr Fell praised involved parties for their contributions, calling the project a "true collaborative effort" with help from national and regional government as well as the Civil Aviation Authority.
A DfT spokesperson said: "We strongly encourage the Peel Group to work with local leaders to find a solution for the Doncaster Sheffield Airport."