Gatwick Airport has accused Heathrow Airport of having a £6 billion ($9.2 billion) black hole in its expansion plans after it was confirmed the UK government will not pay for required road and rail improvements.

The government’s transport minister, Robert Goodwill, told parliament that the airports will be responsible for any surface access improvements required with expansion.

As part of Heathrow’s plans, it would be required to spend about £6 billion on road and rail work, including re-routing the M25 motorway into a tunnel under the airport.

Goodwill told parliament: “In terms of surface access proposals, the government has been clear that it expects the scheme promoter to meet the cost of any surface access proposals that are required as a direct result of airport expansion and from which they will directly benefit.”

The two airports are trying to convince the government they should have a runway instead of the other. In July, the government appointed Airports Commission recommended Heathrow should have a third runway. In response, Gatwick, seeking a second runway (expansion picture above) has been saying it will deliver it cheaper and easier. The government is expected to formally respond to the Airports Commission by the end of the year.

Gatwick Airport chief executive officer, Stewart Wingate, says: “There is now a £6 billion black hole at the heart of Heathrow’s plans. Heathrow has said it won’t meet the bill and now the government has done the same. As we approach a decision on expansion, Heathrow owes taxpayers, passengers, airlines and government an explanation of how they plan to meet it as this cost increase alone is almost the entire cost of the Gatwick scheme.”