This government minister has a really lame excuse for not making a decision on the Heathrow expansion

The government has delayed its decision on whether to build a third runway a Heathrow Airport for at least six months.

A statement put out last night by the Department for Transport says that they need more time to study possible environmental impacts before they finally pass judgment on expanding airport capacity at Heathrow.

The DfT first proposed expanding Heathrow back in 2006.

On the surface, it would appear that the government have broken Prime Minister David Cameron's guarantee that a decision would on Heathrow would be made before the end of this year. But Transport Secretary Patrick McLoughlin told the BBC's Today programme this morning that the decision not to make a decision was actually a decision.

When pushed by the Today programmes John Humphrys on why a decision hadn't been made, McLoughlin said:

Yes and there is a decision. That we've accepted what the report has said that there needs to be airport capacity, but there have been things that have happened that we need to address.

McLoughlin was talking about a report that was released earlier this year by the Davies Commission. The commission was set up by the government in 2012 to give an independent view on what should be done about the future of the UK's airport capacity. The Commission released a report earlier this year that said the best thing to do would be to build a third runway at Heathrow.

This put the government in a very difficult position. While Cameron promised that he would listen to the report and make a decision before the end of the year, it is politically very difficult for the Conservative government to back a third runway at Heathrow.

The current conservative Major of London Boris Johnson is firmly opposed to the third runway and, more importantly for the Conservatives, their candidate to be the next mayor of London Zac Goldsmith is one of the leading campaigners against Heathrow expansion.

It is quite obvious that it would be a very bad decision for the Tories to back the third runway before the London mayoral elections in May next year.

That could explain why McLoughlin was forced into making such a feeble excuse for not making a decision on Friday.

While the Davies Commission did recommend building a third runway at Heathrow, it also said that building a second runway a Gatwick Airport was a viable option.

So the government's logic is that by making the decision to accept the broad summation of the Davies Commission, that London needs more airport capacity, they have fulfilled their commitment to make a decision on Heathrow before the end of the year.

When pushed again on the Today programme over whether a final decision would defiantly be made next year, McLoughlin gave the vague reply - "hopefully."