I was selected as Green candidate for Mayor this week, and the pledges I made at the announcement at Earl’s Court put the Green Party on the front line of a battle for London’s soul.

On Wednesday I stood in the tenants’ hall of the West Kensington estate and joined that battle at the announcement of the Green Party’s candidate for the Mayor of London. It was the perfect place for my first speech as candidate: the site of a ‘regeneration scheme’ that has seen residents wishes bulldozed in favour of big developers, and the scene of the most inspiring campaign to build a different future from the residents themselves.

Where the residents and their local allies see homes, neighbours, playgrounds and trees, developers see only potential profits, and this blinkered view is reflected in City Hall. At Earl’s Court, London’s Mayor Boris Johnson has actively championed the interests of the big developers who want to flatten the West Kensington and Gibbs Green estates. These  developers – promising just 11 per cent affordable housing – are speculating on the land to profit from the sale of safety-deposit-box properties that will never be used as homes by their buyers.

In recent years, around two thirds of new homes built in London have been bought by investors. They are driving up property prices and leaving residents no choice but to rent in one of Europe’s most expensive and least secure markets. The Mayor’s door has always been open to these developers, and it has recently been revealed that many Labour mayoral candidates are also happy to take their money – this begs the question of what they are expected to provide in return.

In contrast, at the announcement I pledged that if elected Mayor I will block the Earl’s Court regeneration scheme by reviewing the decision to include land owned by Transport for London in the deal, and that I will support the residents in their bid to take over their homes and lead the regeneration of their estates. The residents are the best placed people to find space for new homes, to retain and refurbish existing homes, and to ensure this community can thrive.

Earl’s Court will be the first of many schemes run in a different way, because the solution they have proposed is the inspiration for the new policy we announced that day too. My promise is to use City Hall funds and powers to support a resident-led housing revolution.

As part of this, any residents or community groups who want to take control of regeneration in their community, or to propose an innovative new housing development on a brownfield site, will find a friend in the Greens – and resources in the form of a new Community Homes Unit at City Hall. The new unit will provide help, expertise and grants to make resident-led approaches credible and viable across London.

We will prioritise all publicly owned land for these approaches, and promote Community Land Trusts and self-build schemes on a wide range of public and private sites.

The Mayor is the planning authority for the Olympic Park area which includes the Carpenters Estate, the site of the inspirational Focus E15 occupation. City Hall also funds homes built on dozens of regeneration schemes, and is the strategic planning authority for the capital. With the Community Homes Unit and these powers we can help reshape development in London for the benefit of ordinary Londoners. We will kick the big developers out of City Hall, and bring Londoners in.

And whether or not I am elected Mayor, I will lead a group of Green politicians to block Earl’s Court from the London Assembly. Next May we aim to increase our Assembly Members and hold the balance of power in City Hall once again, as we did from 2004 to 2008. During that period, Jenny Jones and Darren Johnson’s leverage over the budget helped block the Thames Gateway motorway bridge and led to half a billion pounds being spent on cycling. Their influence has also seen the creation of the London Living Wage unit and the exposure of abusive undercover policing, along with many other achievements in the fifteen years they have sat on the Assembly.

This is a very exciting time to be standing for election in London, a city where citizens are already getting active and demanding safer and less polluted streets and more humane policing, organising for fairer pay, and standing up to developers who have their estates in their sights.

My campaign to be selected as candidate for Mayor championed these campaigns and promised that the Greens would give them a voice in this election. As Dave Hill wrote in the Guardian, our housing policies exemplify our unique approach to giving the power to shape our city back to Londoners. If London Green Party’s campaign over the next eight months can take the side of citizens who are hungry for change and make their causes our own then – together next May – we can take City Hall.