The UK is becoming increasingly prone to flooding because of the effect of government cuts on flood protection, according to the National Audit Office (NAO).
A report from the NAO warns that half of the countries defence against flooding has been left with "minimal" maintenance and that they are likely to "deteriorate faster" as a result of the waning budget.
The spending watchdog continues that government spending on flood defence has been cut by 6% in real terms under David Cameron's watch.
Some five million homes were at risk of severe flooding towards the end of 2013 as a result of the cuts, says the report.
The government spent £270m on combatting potential floods in that period after the weather took a turn for the worse, which led to Cameron saying that the coalition was spending more than ever before on prevention of floods.
However, the NAO says this is not the case.
Amyas Morse, head of the NAO, said: "Against a background of tight resources, the Agency has improved how it prioritises its spending, including on the maintenance of flood defences. On this measure the agency is achieving value for money.
"However, if we set aside the emergency spending in response to last year's floods, and give due credit for efficiency improvements, the underlying spending on flood defences has gone down."
Chair of the Commons public accounts committee, Margaret Hodge, said: "I am deeply concerned that current levels of spending are not enough to maintain flood protection, with five million homes at risk of flooding and people's livelihoods in jeopardy."
However, flooding minister Dan Rogerson said that the NAO's calculations are incorrect.
"The NAO has drawn conclusions on funding based on inappropriate comparisons. We have invested £3.2bn in flood management and defences over the course of this parliament which is a real-term increase and half a billion [pounds] more than in the previous parliament. This has allowed us to protect 165,000 families and households in vulnerable areas," he said.