An MP has warned the Government a controversial "flight tax" is putting hard-pressed airports in rural areas at risk.
Stephen Gilbert, Liberal Democrat MP for St Austell and Newquay, said the Air Passenger Duty (APD) was having a "disproportionate effect on regional airports operating lifeline routes with modest passenger numbers".
His comments come amid doubt over the future of Newquay airport amid losing its direct link to the capital, and the closure of Plymouth airport.
APD is charged on all passenger flights from UK airports. Introduced in 1994, it has since January 2007 increased by up to 260% for short-haul flights and up to 360% for long-haul flights. APD costs £13 for a short-haul flight and up to £92 for a long-haul journey.
Mr Gilbert raised the tax during Treasury Questions in the Commons as it was highlighted how routes increased in Barcelona due a reduction in APD.
He said: "Air Passenger Duty can also have a disproportionate effect on regional airports operating lifeline routes with modest passenger numbers, such as Newquay's.
"Will the Minister factor that into the discussions she is having with colleagues on the future of Air Passenger Duty?"
In response, the Treasury Minister promised to look at the evidence and encouraged the Cornwall MP to write to her on the matter. He said afterwards: "Air Passenger Duty simply makes life more difficult for regional airports to compete and is an unnecessary burden.
"Newquay airport is a vital link for Cornwall and I am exploring every possible avenue to ensure that services between the Duchy and the capital continue to run."
The Government last month confirmed the air link between Newquay airport and London is eligible for a state-funded subsidy, with politicians hoping the soon-to-be-axed route can be restored by next summer.
Flights between Cornwall's only airport and the capital are due to end on March 30, raising huge concerns over the economic impact on the far South West.
Flybe said it would be withdrawing from the route in May, saying Gatwick's landing charges were excessive. Earlier this month easyJet, which has bought the landing slots at Gatwick from Flybe and operates seasonal flights to Southend from Newquay, said that there was "insufficient demand" to maintain the London link.
But now the Department for Transport has confirmed to Cornwall Council the route is eligible for a public service obligation (PSO). Imposing a PSO will mean the Government providing a subsidy to an operator to deliver the connection for four years.