Lambeth Council has warned it cannot guarantee a primary school place for every child in the borough by 2015.

It said the demand for school places has risen by 40 per cent in the past four years in some areas and it needed funds for an 800 extra places by 2015.

But it said it was £50m short over the next two years to provide the necessary places.

Now the town hall is asking residents to write to the Government to ask them to release more funding.

The council has received £40m from the government since 2006, for primary school places, and another £12m for 2011-12.

The money went into creating 11 permanent and 13 temporary facilities and 300 additional places since 2009.

The council has spent £500 in printing 5,000 pamphlets, which have been distributed to nurseries and libraries, to gather public support for the campaign, while residents can get help through the council’s website.

Peter Robbins, Lambeth's cabinet member for children and young people, said: "Our schools are full to the brim. We have already added as many temporary classrooms as we have space for but now we need proper investment to permanently expand schools.

"To help us make the desperately needed space, we are asking the government to provide £50m investment over two years.

"Our argument is clear, if we don't get funding, the alternative is to build so-called bulge classes. This approach is an expensive and temporary sticking plaster over the problem."

A Department for Education spokesman said: "The government, in a tight capital settlement for 2011-12, prioritised basic need to support the provision of additional pupil places, including doubling the amount allocated to local authorities to £800m. This has been targeted at areas predicting the greatest increases.

"However, the management and allocation will be informed by the James Review, which is aimed at ensuring that best value for money is achieved and that the maximum number of pupils benefit from the available funding."

London Councils, which represents the city's 32 boroughs, said the shortage of places is an issue across the capital, with a predicted shortfall of around 70,000 places over the next four years.