I'd support this IF the charge was used to lower the fares on the HEx or to build additional rail links to the Reading and/or park and rail sites. If not then it just looks like a HAL money grabbing exercise.

But if the price of a third runway is reducing emissions to avoid air quality breaches and the price of avoiding air quality breaches is discouraging car use on trips to LHR, I'd rather go down the charging route than go with runway number 3.