Flights at Doncaster Sheffield Airport (DSA) will start "winding down" next month after bosses said the business had no future.
Owners Peel Group said on Monday, 26 September, that a strategic review had concluded the airport was "not viable due to its lack of adequate forward revenues and high operating costs".
The company has not set a date for closure, but said flights would start winding down from 31 October.
A consultation process will now begin with airport staff, it said. The airport is thought to employ more than 800 people, with a further 2,700 jobs affected in the supply chain.
Chairman of Peel Airports Group Robert Hough said: "We recognise that this will come as a great disappointment to many. The intractable problem remains the fundamental and insufficient lack of current or prospective revenue streams, together with the airport’s high operating costs.
"Our employees have always been DSA’s greatest asset, and we are grateful to them all, past and present, for their dedication and diligence over the years. The immediate priority remains to continue engaging closely with them over the next few weeks.
"As such, DSA will now begin a formal process of consulting with team members. We will do everything we can to minimise the impact of these proposals and work closely with local authorities and agencies to support our employees through what we know will be an extremely difficult period."
Peel Group has been carrying out a strategic review of operations after announcing in July that the business was struggling.
It said business had been hit by the coronavirus pandemic, a shortfall in passenger numbers and the departure of operator Wizz Air. Tui is now the sole carrier based at DSA.
The suggestion that the airport could close led to protests, a petition signed by more than 100,000 people and a number of public meetings.
Earlier this month South Yorkshire Mayor Oliver Coppard and Doncaster Mayor Ros Jones said a "credible consortium" had come forward interested in taking over the airport.
On Friday, 23 September, the South Yorkshire Mayoral Combined Authority (SYMCA) made an offer of public money to keep the airport running until October next year.
At the time Mr Coppard said: "If Peel genuinely want to safeguard the future of DSA they will accept our offer and allow more time for prospective offers to develop."
But Peel Group chief executive Steven Underwood said accepting funding would only "postpone the inevitable".
He said: "Accepting funds from SYMCA may postpone the inevitable for another 13 months, but it will divert funds away from services on which communities throughout South Yorkshire rely."
The company said "no tangible proposals" had been put forward to save the airport or "address the fundamental lack of financial viability".
Its statement said: "The high fixed costs associated with running a safe, regulated airport, together with recent events materially reducing prospective future aviation income streams, mean that a break-even business plan cannot be identified for the foreseeable future."
Mr Underwood said the company was working to develop a "forward-thinking strategy for the airport site, in conjunction with the £1.7 billion Gateway East development next door, to help unlock vibrant, job-creating alternatives to ensure future growth and prosperity."
He added: "We have the potential to attract cutting-edge, future-tech businesses to South Yorkshire, but only if we are able to collaborate with our local stakeholders and community in South Yorkshire."
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