Shaun Bailey is a member of the London Assembly and the Conservative candidate for Mayor of London

It’s easy to forget in these hyper-partisan times, but politicians of good faith can have differing opinions on how to best solve our problems. And so it is on the question of how to tackle London’s dirty air.

Do we try and tax the problem away? Do we expand public transport? Do we lean on advances in technology? Or do we do a bit of everything?

Whatever your preferred approach, every Londoner wants clean air to breathe. As asthmatics, I know my boy and I do. That’s why politicians from all parties have been taking action over the years to clean up our air. For example, Sadiq Khan has recently put Boris Johnson’s central Ultra Low Emission Zone into practice.

This cross-party cooperation is needed, because clean air is a problem London has struggled with for decades. It is a problem we are likely to struggle with until the internal combustion engine is replaced by electric power. The good news is things are getting steadily better, despite the doom-mongering from some quarters.

This is no excuse to let up. In particular, London needs less NOx and other particulates lest another generation grows up having difficulty breathing – or suffer from even worse health outcomes.

But that doesn’t mean one tool is right for all occasions. For example, I support the central ULEZ, but oppose Sadiq Khan’s proposed expansion of it to the North and South Circulars.

If we’re going to try and modify people’s behaviour using hefty taxes (and the ULEZ is £12.50/day and applies 24/7 all year round), there needs to be an alternative for those without the means to pay. The central ULEZ is fair, because central London is also well served by relatively cheap public transport. Getting into central London using public transport is relatively easy too.

Along with the region around Heathrow, central London is also home to the worst of London’s pollution. The introduction of the charge should reduce congestion, make our buses a better transport option – thereby raising TfL’s revenues – and improve the quality of life where so many of us either live or work.

Zones 1 and 2 also have the necessary enforcement infrastructure in place; cameras already enforce the congestion charge, so using the same tools to enforce the central ULEZ is relatively easy and inexpensive.

But there is no ULEZ infrastructure in the Mayor’s proposed expansion zone. It would have to be installed from scratch at an estimated cost of  £130m. And then there is the relative lack of public transport options in Outer London. Outer Londoners need their cars to make the school runs, get to our doctor’s appointments, and get to work; the North and South Circular ULEZ would effectively split these communities in half.

Hitting these Londoners – many of who are already struggling with London’s sky-high cost of living – with a tax for driving when they have no alternative is unfair, especially when there are other ways we can take action to clean up our air.

Top of the list is cleaning up our buses and our taxi fleets. Hybrid taxis are here, and more and more hybrid or low-emission buses are being rolled out too. Speeding up that process will deliver a huge boost to our air quality.

Instead of setting up the kit to make the North and South Circular ULEZ work, we should be using it to upgrade our fleets. We should be getting our delayed tube improvements back on track and expanding the bus network in Outer London. If we’re making car travel more expensive, we need to make our bus network more expansive.

Having more electric charging points would also encourage Londoners to make the switch to environmentally-friendly vehicles, and a light touch regulation system would get more of London’s transport technology start-ups on the road.

To be sure, pricing incentives have a role to play. But any price signal system also needs to be properly thought out. The fact that the expanded ULEZ zone gives a pass to Ferraris while targeting Ford Fiestas shows you that something hasn’t been thought through. Other flaws in the design of the North and South Circular ULEZ are sure to be revealed over time.

And that’s a shame. Because the surest way to turn people off much-needed policy action is to botch its introduction. We need to move quickly on air quality, but we also need to move intelligently. Focusing our time and money on the things we control and where it can have the biggest and longest-lasting impact will be my priority as Mayor.