Let's be clear. Cameron has already U turned on Heathrow

David Cameron is dressing up the inquiry he is about to launch into Airport Expansion at Heathrow as not a U turn - because he only promised not to expand Heathrow in the current Parliament.

But that's not true.

Here's what David Cameron said in 2008:

"I think the whole country can agree that the most important priority for Heathrow is making it better, not bigger," Cameron told environmental group leaders. "And yet Gordon Brown is pig-headedly pursuing a third runway just to try and prove a political point. What a ridiculous way to plan for the future."

Cameron said his objections to Heathrow were not just on environmental grounds. "The case for a third runway is based on Heathrow as an even bigger hub airport with a massive increase in the number of transfer passengers," he said. "The economic value of transfer passengers is hotly disputed. And there are so many examples of the hub model going wrong ..."

Even considering a  third runway is a U-turn. Don't let Cameron pretend otherwise