A proposal for a new fast rail line linking Heathrow and Gatwick has been greeted with scepticism by airlines according to BAR UK.

The costly and lengthy development - termed ‘Heathwick’ - offers no solution to the urgent need for additional airport capacity in the South East according to the Board of Airline Representatives in the UK (BAR UK) which represents 86 airlines.

Mike Carrivick, BAR UK chief executive, said: “Linking Heathrow and Gatwick by rail does not create a viable hub airport and flight connecting times would not be competitive with other airports.

“We do not see how the estimated £5 billion can be justified, even if paid for by others.

“Building an aviation policy around this concept is misguided and if airlines and airports believed a rail link could work it would have had their support years ago.”

BAR UK represents 86 scheduled airlines in the UK in their dealings with government, government departments, regulators and airport operators.

International Airlines Group chief executive Willie Walsh also added his voice to the debate over the proposals over the weekend, suggesting the development could be inefficient and costly.

Walsh expressed concerns about how the high speed rail link would be funded and described it the proposal as “sub-optimal”.

The £5 billion service would enable travellers to get from Heathrow to Gatwick in just 15 minutes via 180 mph trains that would travel underground along the M25, departing every five minutes.