Business leaders have expressed disappointment at another delay to the start of commercial flights at Carlisle Lake District Airport – but remain positive the economy-boosting project will eventually take off.

Both Cumbria Chamber of Commerce and Cumbria Tourism have vowed to support the project after airport operators Stobart Group announced that flights would not take off until next Spring.

The company had already pushed back the start of commercial flights from June to September because of problems with recruiting air traffic controllers – a challenge facing operators around the world.

Yesterday (Monday), Stobart Group pushed take off back another six months or so, citing the same problem with air traffic controller recruitment but also revealing that some areas of the "construction programme require additional time to achieve regulatory approval".

The second delay is another blow to Stobart Group and its carrier Loganair, who were ready to offer flights from Carlisle to London Southend, Dublin and Belfast.

And while speculation bubbles away that the project to bring commercial flights back to the airport for the first time in 25 years may never happen, business leaders remain optimistic.

Rob Johnston, chief executive of Cumbria Chamber of Commerce, said he did not think the latest delay was a call to panic stations and that the wait would be worth it.

“This further delay is disappointing but it’s not the end of the world,” he said.

“Stobart Group and Loganair have reaffirmed their commitment to Carlisle. Stobart have invested heavily in the runway and in a new terminal building. We don’t think they are about to walk away.”

He added: “Flights from Carlisle should bring huge benefits for Cumbria’s economy. We’ve been waiting since 1993 for this service to get started. If we have to wait a little longer for Stobart to get everything in place, then so be it.”

The project had been much anticipated by Cumbria’s tourism industry in particular, with the prospect of offering air links to the doorstep of the Lake District National Park and opening up the visitor economy in The Borders – a key plank of The Borderlands initiative.

Cumbria Tourism’s managing director, Gill Haigh, said she too was disappointed by the delay but was pleased to see the commitment from Stobart Group to commencing flights in the Spring.

She added: “The launch of flights from Carlisle Lake District Airport will be a great boost for Cumbria’s connectivity and our £2.9billion tourism industry and therefore, we will be offering our support to ensure flights are welcomed to the county from early next year.”

Kate Willard, head of corporate projects at Stobart Group, said all efforts were now focused on meeting the latest target date. She had previously pledged there would be no more delays after flights were first pushed back from June.

She said: “We have been working around the clock and physically we are ready. But it is extremely important that this major project, which will connect the region to the tourism and business hubs of London, Dublin and Belfast, is safe and operationally compliant so as to be sustainable in the long term.”

Meanwhile, flight operator Loganair has once again started the process of communicating with affected customers and said it has also updated its website with the options available to them.

The company also expressed its disappointed at the latest delay but stressed it remained “fully committed” to its partnership with Stobart Group to start flights from Carlisle.

More than £12 million has been invested in the airport’s new runway, terminal building and car parking, while Stobart Group has stressed that ticket sales have been “great”.