With ticket prices increasing on busy routes, any increase in passenger duty will have a big price effect on more-price-sensitive traveling families and make them switch to smaller/alternative airports.
This is some tough talk by a man who's knees deep in labor problems and consolidation issues of his own making, but it will likely force movement on the ongoing saga of Heathrow's new runway.
The delay for a decision about London's air-travel future will likely produce more difficult choices as airlines weigh using Gatwick for the international connections they can no longer guarantee at Heathrow.
What with an opinionated mayor who wants and airport island, bickering airport operators who want new runways, major airlines that want to increase capacity, and a population enamored with carbon emission restrictions, London's runway drama isn't going to wrap up any time soon.