The Tories claim the new deal would stimulate building 100,000 extra starter homes on brownfield land.

Homes built under the planned Help to Buy Starter Homes scheme would be exempt from a range of taxes, enabling them to be sold at a discount on the normal market rate.

Cameron said requirements such as building a portion of social housing as part of any development would be waived.

The zero carbon homes standard, which applies from 2016 and aims to improve energy efficiency, would also be exempted.

Cameron said: “We want to help more young people achieve the dream of home ownership so today I can pledge we will build 100,000 homes for young, first-time buyers. We will make these starter homes 20 per cent cheaper by exempting them from a raft of taxes and by using brownfield land.

‘I don’t want to see young people locked out of home ownership. We’ve already started to tackle the problem with Help to Buy mortgages, and these plans will help tens of thousands more people to buy their first home.”

The announcement came after Communities Secretary Eric Pickles unveiled a “Rent to Buy” programme of loans totalling £400m for housing associations and developers for them to build 10,000 homes.

The properties would be subject to a rental cap at 80% of market value for seven years, after which occupants will have the opportunity to buy.

The loan pot will be split 50:50 between London and the rest of England.

London Mayor Boris Johnson will administer the capital’s £200m allocation of the fund, where it will be known as the London Housing Bank.

He said developers and housing associations could bid for loans to bring forward phases of developments that may otherwise not happen for a considerable period of time, and would be given up to 16 years to repay the capital.

‘We hope to provide thousands of brand new homes many years sooner than would otherwise be possible,’ he said.