Nearly seven in 10 Londoners say they are appalled by homelessness in the capital, according to a survey. The YouGov poll, commissioned by the newly launched Lead London Home campaign, reported 68% of respondents saying they either tended to agree or strongly agreed that they found the scale of the city's homelessness problem appalling.

In the 2014/15 financial year, there were 55,430 homelessness cases reported to local authorities in London, according to government statistics. That was up 4% on the previous year and accounted for 32% of all homelessness in England. Critics of the government say its welfare cuts and strict sanctions regime for those on benefits is forcing more people onto the streets.

London has a serious shortage of housing supply. Social housing waiting lists, rents and house prices have spiralled in recent years. The city's population, currently 8.6 million, is forecast to hit 10 million within the next few years. The ONS says more than one in 10 households are now defined "overcrowded" in London, a worsening problem as the city becomes more densely populated.

Lead London Home is a partnership between a number of housing and homelessness charities in the city. It includes Crisis, St Mungo's, Centrepoint and Homeless Link. It is calling on the next mayor of London, to be elected in May 2016, to make tackling homelessness a priority. The two front-running candidates are Labour's Sadiq Khan and the Conservatives' Zac Goldsmith.

"The priority after May must be prevention, including helping those with the most complex needs and providing specialist support for vulnerable and minority groups," said Rick Henderson, chief executive of Homeless Link. "For those already homeless it is vital to ensure that there is a clear route off the street, as well as investment in new homes. Ultimately the mayor of London not only has the opportunity to act but the platform to be a voice for those who are most in need of representation. Whoever wins in May must use that opportunity."

A symptom of rising homelessness has been the rise of controversial spikes used outside the city's residential and commercial premises to deter rough sleepers. Boris Johnson, the current Conservative mayor of London, called the anti-homeless spikes "terrible".

The Lead London Home manifesto, published for its campaign launch, calls on the next mayor of London to...

1. Lead a new drive to end rough sleeping, including providing at least 2,000 homes and a Housing First programme for former rough sleepers.

2. Prioritise homelessness prevention and support calls for a new law so that no one can be turned away by councils to sleep on the streets.

3. Increase access to private rented sector housing and tenancy support for people on the lowest incomes.

4. End destitution by working across the European Union to find solutions to EU nationals sleeping on the streets.

5. Embed the needs of homeless people at the heart of London's public services.

6. Fight for a better deal for London to mitigate the negative impact of welfare reform on people who are homeless and at risk of homelessness.