"In the midst of this crisis, groups of campaigners and local residents have fought tirelessly to protect what

If Sadiq Khan really wants to be a ‘mayor for all Londoners’ he must fight for social housing

He's been mayor of London for less than week but already campaign groups are piling the pressure on Sadiq Khan to take action on the big challenges facing the capital. In the last few days, there has been a protest outside City Hall about the need to safeguard women's refuges, calls for him to deliver on his promises on cycling, and a request for a statue of a suffragette in Parliament Square. These are all important issues but the most pressing problem for him right now has to be solving the capital's housing crisis.

In recent years, local authorities right across the UK have struggled to deal with rising homelessness but nowhere has the problem been more stark than in London. One big cause of the rise is the severe shortage of social housing. This problem has been compounded by estate regenerations which have meant thousands of people have been moved away from their support networks and entire families have been forced to live in bedsits, as their old homes have been torn down to make way for luxury apartments. Estate regenerations currently in progress will lead to the loss of at least 7000 social homes across the city.

But, in the midst, of this crisis, groups of campaigners and local residents have fought tirelessly to protect what's left of London's social housing. And they've made a real impact. Without them, the numbers of people being shipped out of the capital would surely be much higher. Almost every week there are call outs on Twitter for support to protest against plans by one local authority or another.

Newham council has often found itself on the receiving end of campaigners' fury. One of the most prominent housing groups is the Focus E15 campaign, which was formed after a group of young mums and their children were evicted from a hostel in Newham. Ever since then, the group has been a thorn in the side of the council. They hold regular meetings, have a weekly street stall and support and protest on behalf of individuals who are at risk of losing their home.

The latest battle Newham council faces, is over plans for the development of West Ham United's Boleyn Ground. Earlier this week, the team played their last game at Upton Park before the club moves to its new home at the Olympic Stadium in Stratford. It was an emotional night for fans and marked the start of big changes for the local area, with many pubs and street traders fearful for their futures. But it's the plans for new housing on the site which has proved most controversial.

Initially, the developers Barratt Homes and Galliard Homes put forward a proposal which included no plans at all for social or affordable housing. But Newham council negotiated a deal which will see 211 of the 842 homes built, being "affordable". The mayor of Newham, Sir Robin Wales, also announced an additional investment of £18m to provide a further 10% of "affordable homes" on the site.

So have campaigners got what they want? Well not really. Yes, the new plan is clearly an improvement but there is still no provision for much needed social homes and it's still not clear how 'affordable' these new homes will be.

The council says that around 50 homes will be available at 50% of market rent which is comparable to how much a social rent would be. The other "affordable" units will be available at up to 70% of market rent.

"We have worked closely with the developers to maximise the affordable housing offer on this important site," Councillor Ken Clark, chair of the strategic development committee said at the time the plans were announced. He added: "The progress we have made has been incredible moving from zero to 25% affordable housing on site."

With the cost of London rents soaring, these plans don't fill campaigners with much joy. At the forefront of the protests against the proposals is the Boleyndev100 group. They have called for 100% of the site to be used for social housing and argue that the new homes will be out of the reach of most local people. In a recent blog post the group wrote:

"Despite over 700 objection letters submitted by our campaign and 11 objecting speakers, the Strategic Planning Committee approved plans for the Boleyn Ground development with only 25% so called “affordable housing” and no social housing.

"Instead, it approved plans for yet another “safe deposit box in the sky” luxury development. As if this is isn’t bad enough, it’s offering a public subsidy of £18.5m to bring it in line with its own policy. You couldn’t make it up."

This is a perfect example of what has been happening right across the capital. Luxury apartments are popping up everywhere, but they are not designed to help the people who are most in need. Instead, they are intended solely to make a quick profit for developers. Companies may be forced to chuck in a few "affordable" homes here and there but plans for new social housing are few and far between. It's much more attractive for a cash-strapped council to flog off land than it is for them to build their own properties to rent out.

And this is the big challenge facing Sadiq Khan. There is a massive shortage of social housing in London but at a time when local authorities have had their budgets slashed the prospect of new council estates being built seems unlikely. Yet the housing crisis will never be solved by the mass development of luxury homes with a few crumbs being thrown to the slightly less well off in the form of "affordable homes".

The former mayor Boris Johnson once promised to fight against the "Kosovo-style social cleansing" of the poor from London. Yet under his watch London's housing challenges have turned into a full-scale crisis. Last week Sadiq Khan was elected on a promise to be a "mayor for all Londoners." Now is the time for him to prove it.