The Public Accounts Committee (PAC) report on flood-proofing England also said an additional 203,000 properties are at risk of flooding because existing defences have not been maintained.

And it said the problem will get worse as the climate warms.

It comes just weeks after heavy rain from Storm Henk flooded more than 1,800 properties, and on the same day a separate review warned London is "underprepared" for the impacts of climate change like flooding and hotter weather.

The committee called it "unforgivable" that "new housing continues to be built in areas of high flood risk without adequate mitigations".

Committee member Anne Marie Morris, an MP in flood-prone Devon, told Sky News the "desperate rush to ensure that housing targets are met" meant that "land which shouldn't be used" is being built on with "workarounds".

Over half of local planning authorities rarely or never check whether a new development complies with flood risk measures, according to a survey by the environment department (Defra).

The Environment Agency (EA) had told the committee that "a number of… quite large" planning applications had been approved by the planning inspectorate, despite EA warnings "there was no robust plan to build the necessary flood defences".

Sky News asked the Environment Agency via Defra to provide examples, but the request was not answered at the time of writing. However, Sky News spoke to four experts in flooding who confirmed the trend.

Dr Jess Neumann, a hydrologist at Reading University, said planning applications "for thousands of homes are still being approved in high flood risk areas, placing new homeowners at an increased and unnecessary risk of flooding".

She said it is possible to "build safely in flood prone areas" provided the homes are well-designed, for example by building them on top of a garage, raised banks or stilts.

But as flooding worsens with a hotter climate, we "can't just keep building our defences higher and higher".

In the case of Storm Henk, the "sheer amount of water" made it "pretty much impossible to avoid or prevent the floods", she said.

What can be done?

Dr Morris said it was not just a question of funding, but that tightening planning rules and assigning more local planners would help avoid homes being built without flood protection.

She urged the government to "take it seriously. Recognise that there is a big issue here, and it's going to get worse before it gets better".

The committee warned smaller communities of fewer than 100 were missing out on funding for flood defences because they were too small.

Experts have also suggested measures such as early warning systems and more nature-based solutions that soak up the water upstream.

A Defra spokesperson said they would "consider the PAC's recommendations as we continue to work closely with the Environment Agency to protect hundreds of thousands of homes from floods".

Since 2010, £6bn of investment has protected homes around the country, including 102,000 during Storm Henk, they added.

A further record investment of £5.2 billion between 2021 and 2027 will "better protect hundreds of thousands of properties across England", they said.

Particular risk for London

Today's report on flooding in England is one of several in the last two years to warn the country is ill-prepared to cope with a changing climate, including from the National Audit Office, the National Infrastructure Commission and the Climate Change Committee.

Another published today warned London is "unprepared" for the more intense heat and flooding it has already experienced due to climate change, calling for a "step change" in ways to help the UK cope with the impacts.

The London report was commissioned by the mayor Sadiq Khan after the capital was hit by flash floods in 2021 and the 40C heatwave in 2022 drove wildfires and a hospital IT system meltdown.

How is climate change affecting the UK flooding?

Floods are becoming more common and more severe in the UK as the climate warms, as hotter air can hold more moisture.

That means rivers overflow, but also that cities flood because the rainwater has nowhere to go in a heavy downpour, running off paved roads and driveways rather than seeping into the ground.

A spokesperson for the Local Government Association (LGA) said councils "need greater control over funding into flood defences across their areas.

"Councils will always seek to minimise flood risk when considering new housing and follow the Environment Agency's flood risk advice on planning applications.

"The LGA has called on government to enable urgent acceleration of local adaptation action as part of the National Adaptation Programme."