The report found a �2bn funding gap in government plans

The study, for seven counties, examined services needed to support planned new homes, like transport and schools.

It found the infrastructure cost to taxpayers of building 572,000 new homes in the next 20 years will be nearly �30bn - �2bn more than predicted.

The Office of the Deputy Prime Minister said it was committed to making sure the housing growth is sustainable.

Councillor Keith Mitchell, who chairs the South East County Leaders (SECL), said the results of the study were "a wake-up call to policymakers".

SECL represents East and West Sussex, Surrey, Kent, Hampshire, Buckinghamshire and Oxfordshire.

It commissioned the report, called The Cost & Funding of Growth in the South East of England.

'Already over-stretched'

Consultants Roger Tym & Partners looked at government plans for 28,000 homes per year.

Areas proposed for new housing include Ashford in Kent, Gatwick, the Thames Gateway, parts of Surrey and along the Sussex coast.

"Our infrastructure is already over-stretched," said councillor Tony Reid, deputy leader of East Sussex County Council.

He acknowledged new housing was needed but said the SECL wanted "government commitment to invest in the necessary infrastructure".

A statement from the Office of the Deputy Prime Minister said that "infrastructure lies at the heart of the sustainable communities plan".