Housing chiefs have rounded on Conservative plans to extend Right to Buy to 1.3m tenants in housing association properties.

The concerns were raised ahead of publication of the Conservative General Election Manifesto, which will outline plans for widening the reach of Margaret Thatcher’s landmark policy.

To fund the £4.5bn annual cost of the scheme, councils will be forced to sell off their most valuable 210,000 social homes as soon as they became vacant.

Party leader David Cameron is expected to say today: ‘Conservatives have dreamed of building a property-owning democracy for generations, and today I can tell you what this generation of Conservatives is going to do.

‘The next Conservative Government will extend the Right to Buy to all housing association tenants in this country - 1.3 million extra families; a new generation given the security of a home of their own.

‘So this generation of Conservatives can proudly say it: the dream of a property-owning democracy is alive - and we will fulfil it.’

Around 1.88m council homes are thought to have been sold under Right to Buy since it was launched in 1980.

The National Housing Association warned today that local authorities had only built ‘just over 345,000 homes’ to replace these properties, adding that the potential extension of Right to Buy was the ‘wrong answer’ to the housing crisis.

Gavin Smart, deputy chief executive of the Chartered Institute of Housing, added: ‘Extending Right to Buy to housing associations is not going to tackle the housing crisis – in fact it could make things worse for people on lower incomes who are already struggling to access a decent home at a price they can afford.’

‘The Conservatives say that forcing councils to sell off their most valuable properties would fund this extension plus 400,000 new homes over five years – we fear the figures simply won’t stack up.

‘And it could have a huge impact on councils’ ability to build new homes, particularly in more expensive areas like London and the south east, where it might actually make more sense for them to borrow against the value of these properties so they can fund more homes,’ Smart added.

Simon Parker, director of body the New Local Government Network, said: ‘Forcing councils to sell-off their highest value properties is simply bad policy. Money should not be taken from hard-strapped local authorities to fund a central pot to compensate housing associations for the Conservatives’ decision to introduce Right to Buy with high discounts to their tenants.’