The boss of easyJet has claimed it is "very unfair" to expect airlines to fund airport expansion in the South East in advance of the work taking place.

Carolyn McCall, chief executive of the no-frills airline, insisted that "quite a big negotiation" will have to take place whether Heathrow or Gatwick is chosen.

The Davies Commission recommend last July that a third runway should be built at Heathrow, at a cost of £18.6 billion.

But ministers have postponed a final decision pending new analysis of the environmental impacts.

Other shortlisted options are extension of the existing northern runway at Heathrow - costing £13.5 billion - or building a second runway at Gatwick, which would cost £9.3 billion.

Willie Walsh, chief executive of British Airways' parent company IAG, has previously described the cost of Heathrow expansion as "outrageous" and insisted "we wouldn't be prepared to pay for or to support the development".

Ms McCall - who is backing a third runway at Heathrow despite having an existing base at Gatwick - echoed his comments.

Speaking at Italy's Venice Marco Polo airport, where the airline launched its latest base, she told the Press Association: "There's quite a big negotiation to be had between airlines and Heathrow before people assume how they're going to be pre-funding.

"Wherever it's built, pre-funding is a massive issue for airlines - and therefore for airline passengers - regardless of the airport. Heathrow and Gatwick are in the same boat on that.

"I completely understand BA's point of view at Heathrow because we would have the same point of view at Gatwick, which is pre-funding doesn't work.

"Basically you're getting airlines to pay for your infrastructure development before anything is delivered and it can take you 10 years for it to be delivered.

"It's a very unfair way of funding infrastructure development which is to the benefit of the country."

She added: "There are lots of negotiations to be had between Heathrow and airlines, including us, as to how we would operate at Heathrow and at what cost and with what infrastructure."

Ms McCall also expressed her frustration that a final decision over where expansion should take place was delayed in December.

She said the UK's attitude to airport capacity is "frustrating" by comparison to the rest of Europe.

"It's not good for aviation because we've been waiting for a very long time for this decision," she explained.

"Davies came out with a very clear-cut recommendation, and I think by delaying it's got everybody going: 'What's that about, what does this mean?'.

"So it's more uncertainty and I think it's frustrating when you go to Europe and you see how clear their visions are about their primary airports.

"There's none of this (uncertainty). They drive capacity and expansion. They do it with all the stakeholders. The key players are very aligned and it really works for them. It works for their economies and it works for the aviation industry."

Meanwhile Andrew Tyrie, chairman of the influential Commons Treasury select committee, has written to Chancellor George Osborne calling for more details of the calculations which led to the Davies Commission recommending Heathrow.

He said the Commission's case was "opaque in a number of important respects" and that "a good deal more information is required" if the Government's decision is to be properly scrutinised.

A Department for Transport spokesman said the Commission had provided "exhaustive detail".