I have to begin with a confession. I use Heathrow at least once a week and have done so for the last 6 years. I can’t even being to recall the number of times that I’ve circled the skies above the airport or been delayed at either take-off or landing by a late running service. So I ought to be a natural champion of the expansion plans.  Except for one thing: I live in Putney and I’m one of the 725,000 people who is currently affected by the airport.

It’s worth repeating that 750,000 figure because the comparable number for, say, Gatwick is only 11,900. It’s a historical mistake to have a major airport to the west of the city and then given the prevailing wind have no choice but for planes fly directly over it. That’s why no other major city in the world does that. Expansion will push that number of people impacted close to 1 million. That’s not a minor local issue faced by a few NIMBYs it’s a population equivalent to a city the size of Birmingham.

Britain needs a world class hub airport, one which can compete with the very best in the world. So it’s hard to understand why Boris Island was so readily dismissed. It’s a classic typically lack of vision combined with a British make do and mend approach. If we want to be a global hub with many more flights to the growth areas of Asia and Latin America, build a giant 7 runway airport and a fast speed connection to central London. The money would be raised and the borrowing cost available to government is at record lows if not. It’s hardly the stuff of fantasy when building an airport from scratch is something the Chinese manage to do at a rate far quicker than once a month. Often they are aided by British firms like Fosters and Partners who provide the design and expertise.

Heathrow, given its location, cannot do night flights and it cannot end runway alternation (nor is the current proposal suggesting it would). With both those constricting factors Heathrow will continue to flag behind its European rivals. Schipol has six runways and Paris Charles De Gaul four, so do Frankfurt and Madrid. There isn’t the space to put a fourth runway at Heathrow so adding a third is merely a short to medium term improvement. Heathrow is going to reach capacity again within a few years. The DFT’s own figures show 50% more people will travel through UK airports by 2030. A third runway will not give Heathrow the capacity to compete for long even with the shift to bigger carriers.

Much is made by its supporters of Heathrow’s economics benefits. Yet the Governments own analysis released just this week showed that expanding Gatwick would yield £54 billion in economic benefits — marginally less than the £61 billion attributed to Heathrow. The abandonment of the Davies figures is highly significant because it also severely alters the regional benefits used to justify this as a national decision. For example Scotland’s £14bn is slashed to £4bn over 60 years. Yes that’s 60 years!

For me an acceptable answer to the need for more airport capacity would have been another runway at Gatwick whilst the Boris Island project was undertaken. In doing so it would have sent a great signal to the world that we had the vision and determination to truly go global. I’m a Conservative and I also happen to believe competition to be a good thing. Heathrow is already expensive in terms of landing fees and will be over dominant unless it faces greater competitive pressure.

It would also have meant less of an immediate hit to the taxpayer. The alterations to the M25 etc… will require billions of direct state subsidy when Gatwick could proceed without it. Fewer people would be impacted, fewer homes would be demolished (242 at Gatwick versus 783 at Heathrow) while being a cheaper project and being delivered quicker.

Both Davies and Theresa May have said that the airport could not be expanded without meeting legal limits on pollution. What they haven’t said is how they think that can happen. There will be nothing worse for our global standing and the PM’s credibility for Heathrow to fail yet again in the courts. Yet, that’s exactly what I believe will now happen as four Tory councils seeking to challenge the decision on the ground that Heathrow poses a health hazard. My local Council, Wandsworth, is one of them and it’s great to see it once again standing up for local residents.

Heathrow is the only major UK airport where air pollution levels remain stubbornly above EU legal limits. I’m no fan of the EU: I voted to leave it. But I don’t see why an independent Britain would want less stringent pollution controls than a Britain which is a member of the European Union. The European Union’s Directive on Air Pollution has set legal limits which now need to be met by 2020.  Even with the Great Repeal Bill these limits will be enshrined in British law. In the Heathrow area the pollution comes from the planes but also from the traffic on the nearby motorways.  Colin Matthews, the CEO of Heathrow until 2014, has said that traffic on the M4 in the vicinity of the airport would need to be ‘diesel-free’ to allow for a third runway to be built. That’s simply not deliverable.

This I fear will prove to be a major stumbling block. Britain is rightly a country which prides itself on the rule of law. Heathrow cannot be expanded if in doing so it breaches legal limits of pollution. That’s to say nothing of the issue noise. Over the past 30 years aircraft have become quieter but this has been offset by the huge increase in the number of planes in the sky.

Our neighbouring constituency will face a by election and I will make the effort to go and support Zac Goldsmith in his campaign. Having made a promise he had to stick by it. I hope my own local MP takes a similarly robust attitude. I don’t expect her to resign as it’s a pointless exercise and she’s never made the same outlandish promises that Zac made. But it will do her personal standing locally real damage if she is seen to soft pedal on this one. Today, local residents require the same fantastic vigour she’s always displayed in the past in opposition to Heathrow expansion.

As a minimum that means contacting the thousands of people on her Heathrow mailing list and actively encouraging them to respond to the forthcoming consultation. It also requires Justine, who has been brilliant local champion, to stand up for her local residents and vote against the plan to expand Heathrow when in a years’ time it comes back to Parliament for approval. Any attempt to dodge the vote by being absent will smack of betrayal. Being a Cabinet Minister does pose an awful conflict of duty. But Heathrow expansion isn’t a side issue in Putney; it’s something Justine has campaigned on since first being selected back in 2003. It’s been a central tenant of the way she’s built her local brand, long before the Conservatives started winning elsewhere. I don’t envy her the choice but the PM ought to accept that her first duty is to the people who elect her.