This week I voted against a third runway at Heathrow. We need to expand our aviation capacity - but I don't believe this should be done at Heathrow. Together with the Mayor of London and Wandsworth Council I have backed calls for the Government to reconsider its position. Like them, I will actively seek to prevent a third runway being built, and will support their proposal to launch joint legal action against the plans. The environmental impact would be disastrous in an already polluted city and would harm generations to come. I've always supported expanding Gatwick - it's cheaper and greener.