London elects a new mayor this Thursday. Unlike most elections, every vote counts in this one – so your choice could help decide whether the Silvertown Tunnel goes ahead or not.

There are many, many issues that will influence your vote, but you may wish to consider the candidates’ views on the Silvertown Tunnel before casting your votes.

You have a first choice and a second choice on the pink ballot for mayor. This means you can vote with your heart with your first preference, and your head with your second choice.

It’s also worth considering the tunnel when voting on the orange paper – the party list ballot that decides some of the membership of the London Assembly, the body which scrutinises the mayor’s policies.

Over the past seven months we’ve been contacting candidates, meeting some of them, reading their manifestos and keeping up with their interviews to find out where they stand on the Silvertown Tunnel.

We’re also grateful that so many other people have also been in touch with them, reminding them that the Silvertown Tunnel is the wrong solution to London’s traffic problems.

Anti-tunnel: Caroline Pidgeon

One candidate has included scrapping the tunnel in her main manifesto – Liberal Democrat contender Caroline Pidgeon. As a former Southwark councillor – and current London Assembly member – she’s well aware that the Silvertown Tunnel is not a parochial issue affecting only Greenwich, Silvertown or Poplar – the extra traffic the tunnel will attract will clog up streets right across east and south east London.

Her manifesto says:

“We will oppose the proposed Silvertown Tunnel, which would exacerbate congestion at a cost of £1 billion.”

We’ve met Caroline and her team and are grateful for her support, which has included asking outgoing mayor Boris Johnson tough questions about the scheme. She also heads her party list for the London Assembly – on the orange ballot paper.

Anti-tunnel: Sian Berry

We’ve also had consistent support from Sian Berry, the Green Party’s candidate for mayor. Her manifesto commits her to scrapping all new roadbuilding projects in London. Local manifestos for east London and south-east London highlight the threat from the Silvertown Tunnel.

“We will cancel plans for new road-building schemes, including river crossings and new road tunnels. Instead, our investment plans will be for new river crossings for people on foot, bikes and public transport.”

Sian spoke at our public meeting in Greenwich in October 2013, and also helped us in her old day job as roads campaigner for our friends at Campaign for Better Transport. She’s been emphasising her opposition to the tunnel in recent weeks, including bringing it to a national audience on BBC Radio 4’s Today programme.

Again, Sian heads the Green Party list for the London Assembly – on the orange ballot paper – where she aims to replace outgoing Green assembly member Darren Johnson, who has also asked tough questions of the mayor about the tunnel. We’d like to thank Darren for his work.

Wants a review: Sadiq Khan

Labour’s Sadiq Khan made his first comment on the tunnel last month, distancing himself from TfL’s proposals. He said they “do not fully take into consideration the importance of greener transport, and imposing a toll is in many people’s minds a tax on East and South East Londoners”.

He added: “We need a proper joined up review, looking at river crossings and improved public transport connections east of Tower Bridge, but in a strategic fashion, not piecemeal like the current mayor.”

And last week he told Londonist:

“My concern is that there’s not a proper plan to have crossings that don’t have an adverse impact on air quality, the environment and the people in the south east of London.”

Five Labour boroughs – Lewisham, Southwark, Hackney, Waltham Forest and Newham – have opposed the current Silvertown Tunnel plans in the most recent TfL consultation, and it’s good to see Sadiq recognise the serious flaws in the proposal.

We’d be happy to meet him and explain more about why the tunnel is bad for London.

Pro-tunnel: Zac Goldsmith

Which brings us to Zac Goldsmith, the Conservative candidate. His campaign team may wave around placards reading “cleaner air”, but in the case of the Silvertown Tunnel, it’s just hot air – he’s a wholehearted supporter.

According to his manifesto:

“I will back a new, privately-financed tunnel at Silvertown as part of my Action Plan for Greater London, with construction starting from 2018… To ensure it doesn’t add to air pollution, I will levy higher charges for dirty vehicles, while offering discounts for the cleanest cars.”

Zac’s basically taking TfL’s current proposal and passing it off as his own, with the addition that he’d charge highly polluting vehicles more to use the tunnel.

This actually risks even worse pollution than TfL’s current plans, as the filthiest vehicles would then start clogging up other streets looking for the nearest free crossing.

For someone who spent 10 years as editor of a magazine called The Ecologist, it’s a frighteningly naive proposal, and deeply disappointing. Maybe he’s being very badly advised. Or perhaps for Zac, clean air only matters in the west of London, where he has campaigned against Heathrow Airport expansion.

Of the other candidates, Ukip’s Peter Whittle has not addressed the Silvertown Tunnel directly, but he has said he is against building new river crossings for cars.

Care about clean air and congestion? Cancel the Silvertown Tunnel

It’s an election where candidates are very keen to boast how much they care about clean air.

Communities across east and south east London deserve clean air as much as their neighbours in west and central London – so we’ll be looking for the next mayor to cancel the Silvertown Tunnel at the first opportunity.

As far as the orange ballot paper is concerned, we can’t emphasise enough how Greens and Liberal Democrats have asked tough questions of the mayor, in contrast to other assembly members. If the next mayor decides to push on with the Silvertown Tunnel, this sort of scrutiny will be badly needed.

Whatever happens on 5 May, we’ll be watching the results closely, both for the mayoral and London Assembly elections.

And whoever wins can be sure of one thing – we’ll be in touch to say hello as soon as they’ve got their feet under the table.

Main photo: Polling Station by Paul Wilkinson, used under Creative Commons licence CC-BY-2.0.