Cllr Mario Creatura represents Coulsdon West Ward on Croydon Council

In March this year the Mayor of London’s office released the results of a survey to discover the top issues facing Londoners.

To the surprise of no-one, housing was the number one priority. Since 2010, house prices in London have increased by 50 per cent compared to the UK figure of 23 per cent with average private rents increasing by 16 per cent against the English average of 6 per cent. It’s a situation that clearly cannot be allowed to continue.

The Mayor’s survey revealed that 85 per cent of Londoners agree that more housing is needed in London. The logic is sound: increase the supply to meet the demand and in so doing reduce the overall cost of the units.

London’s Conservative Mayoralty have a lot to be proud of in this regard. The number of new affordable homes funded by the Greater London Authority has more than doubled to nearly 18,000 in the past year alone. GLA-funded housing starts and completions were up 205 per cent last year compared with just 8,709 in 2013-14. The total number of homes delivered by GLA schemes rose to 19,661, up from 8,892 in the previous year.

Significant progress to be sure, but we all know that’s still not enough to cope with our booming population.

In February, George Osborne and Boris Johnson launched the London Land Commission with a goal to supporting the development of 400,000 homes on brownfield and public sector land by 2025. An admirable ambition, but one that rests on a fundamentally flawed assumption: that we know where the brownfield and public sector land actually is in London.

It is entirely reasonable to expect all of London’s boroughs to have a detailed record of all the brownfield land within their borders – and yet shockingly they don’t.

The London Chamber of Commerce and Industry recently submitted FOI requests to ascertain London’s brownfield land stock. Of London’s 32 Local Authorities only seven were able to provide data on the total number of brownfield land they owned in hectares. As many as seven local authorities were unable to provide any data while three boroughs bizarrely claimed they held no brownfield land at all.

This data deficit is simply untenable. For developers and local authorities to hope to meet the Mayor’s justifiably ambitious brownfield housing targets it is vital this information gap is closed. It can’t be beyond our ability to ensure all London’s boroughs have a consistent approach to gathering and supplying this data to the GLA.

Last year the LCCI recommended that the Mayor of London maintains a register of all brownfield land in London and set a trigger mechanism whereby ownership of long-term undeveloped brownfield land is transferred to private firms or public bodies able and willing to develop them into housing. They’re right to push this issue.

What this essentially comes down to is someone creating a very detailed database. It’s not glamorous, but an appreciation for the vital importance of the task is gathering support. Diane Abbott, one of the Labour Mayoral hopefuls, has already seized on this and pledged to create a ‘Domesday Book’ of brownfield sites. It won’t be long before others follow suit.

Land availability is recognised as being the top barrier to house building in London. With the overwhelming majority of Londoners ranking housing as their top fear, the Conservative Mayoral contender who convincingly tackles this brake on brownfield development will almost certainly be the one to watch in next year’s race.