One million - the number New homes at risk of being flooded

Around a third of the three million new homes that the Government wants to see built by 2020 could be on flood plains, according to the Association of British Insurers (ABI).

"Poor planning decisions will lead to more homes becoming unsaleable, uninsurable and uninhabitable," said Justin Jacobs of the ABI.

In the past year, 13 major building developments have been given the go-ahead despite Environment Agency warnings on the risk of flooding. Seven of those were found to be at high risk of being swamped. Insurers have called for the Government to investigate and justify its final decision if the dangers are disregarded. "Where a local authority plans to ignore advice, the Government should step in, review the proposals and be compelled to publish its decision," said Mr Jacobs. "Its ambitious housing plans are in jeopardy unless we reduce the flood risk."

In a "statement of principles" – part of the discussions between insurers and the Government on the issue – the ABI has pledged that its members will continue to cover existing policyholders against flooding. But Mr Jacobs said tougher planning controls were needed if flood insurance was to remain widely available for new homes. And Stephen Haddrill, the ABI's director-general, said the pledge could continue only if the Government committed to addressing the lessons of last summer, when the unprecedented flooding resulted in £3bn worth of claims – of which £1bn has been paid out by insurers so far.

To date, just half of the 15,000 people sheltering in temporary accommodation after the major flooding in Yorkshire, Gloucestershire and Worcestershire have been able to return to their homes. Not all the remaining victims are expected to have returned by Easter.