The insurance industry and the Government have come to an agreement to ensure that householders are able to obtain protection against flooding, it was revealed today.
Under the agreement, insurers will guarantee to provide protection to any property deemed to have a risk of less than one in 75 from flood.
On its side, the Government has committed itself to a long-term 25-year strategy to improve flood defences, said Environment Minister Phil Woolas.
Mr Woolas told the BBC Radio 4 Today programme: "The insurance companies very reasonably said that it is necessary to have a long-term strategy - 25 years is the figure that we are going ahead with.
"We are looking at coastal flooding as well as river flooding and surface water flooding to ensure that the increased investment that we have - and we have increased investment in flood defences quite substantially in this country - is sustained in the long term."
Mr Woolas declined to estimate how many homes may fall outside the one-in-75 risk bracket and be classed as undefendable against flood, saying only: "That is not for Government to declare."
He said it was important that the Environment Agency makes use of new powers to block developments at risk of flood and said that insurers were now ready to offer improved premiums to householders who take action to make their homes more resilient against rising water.
He added: "What has changed is the climate change predictions that the scientists are giving us, that the extreme weather conditions are going to increase in the decades to come.
"That requires a long-term strategy... It is something we have been negotiating with the insurance industry in some detail.
"They, quite understandably, want to have assurances that homes are protected and we, quite understandably, want to do that in any event."