The door has been opened to Gatwick’s bid for a second runway after the transport secretary suggested that the Airports Commission may have got its figures wrong.

Patrick McLoughlin (pictured) said he was open to arguments from Gatwick that the commission was wrong to unanimously rule in favour of expanding Heathrow on economic grounds.

He drew parallels to the west coast mainline when the award of a new railway contract was scrapped, landing the taxpayer with a multi-million pound bill because of major errors in the accounting process.

The commission had ruled that expanding Heathrow would deliver £147 billion worth of economic benefits compared with Gatwick’s £89 billion.

Gatwick claimed the figures were flawed because they underestimated the impact of a second runway.

Speaking to the commons transport committee yesterday, McLoughlin said he was minded to accept the figures but would look into any alternatives, the Times reported.

“Overall I accept what the commission are saying unless it can be somehow proved to me that the commission got their figures wrong,” he said.

“It would be rather stubborn of me to say to Gatwick ‘I completely dismiss everything you have said’. If they want to prove something else I will obviously look at that.”

The development came as Heathrow chief executive, John Holland-Kaye, said the airport was prepared to “significantly reduce the amount of night flying” but refused to back an all-out ban – one of the key conditions to expanding the airport.

The boss of Heathrow has sought to undermine rival Gatwick’s lobbying efforts for expansion while setting out the “stark choice” on offer to the prime minister when considering airport capacity in the south-east.

Holland-Kaye claimed that the decision in December to delay a decision on a new runway paves the way for expansion at Heathrow “as it is the only option that can deliver the government’s commitment of sustainable economic growth and opportunity for all”.

He was speaking out for the first time since the government’s response to the Airports Commission in June, which recommended expanding Heathrow.

He claimed that Heathrow had the only plan with a strong policy basis, following the support of the commission.

Holland-Kaye said David Cameron could choose between Heathrow – “the only location which all the airlines agree is the right one and want to fly from – or one which would not reach emerging markets.

Without naming Gatwick, he said: “You could choose the option that will not get us to emerging markets, which does nothing for the regions of the UK, or for exports, that delivers a fraction of the jobs or the economic benefits, is less financially robust, does not have the support of business or unions, nor the local community, nor the airlines, nor politicians, nor the policy basis of the Airports Commission. That offers local people no respite from noise. That has only one motorway and one railway line.”

Alternatively, Heathrow’s expansion plan is designed to meet government environmental targets and has the support from the majority of local communities, Holland-Kaye claimed.

Addressing the prime minister directly, he described Heathrow as having “the only plan which you know you can get through Parliament because it has the backing of the majority of MPs across all the major parties, as well as politicians in Scotland, Wales and Northern Ireland”.

It is a resilient plan, which puts the airport at the heart of the UK’s transport system, served by five motorways and five railway lines, Holland-Kaye added.