Government spending cuts must not be allowed to affect vital flood defence work, MPs have warned.
The Commons Environment, Food and Rural Affairs Committee said that with more than 5.5 million properties in England and Wales at risk of flooding, it was essential that spending on defences was prioritised.
But with the Department for Environment, Food and Rural Affairs (Defra) facing cuts of 15% in day-to-day spending over the next four years, the committee expressed concern that such programmes could lose out.
The committee welcomed the Government's commitment to a £2.3 billion six-year investment programme for England intended to fund 1,400 flood and coastal erosion defence schemes.
Defra estimates it will reduce risk of flooding for 300,000 households while averting an estimated £30 billion in economic damage.
However, the committee expressed concern that while the plan relied upon raising £600 million from "external contributions", so far it had brought in just £250 million, with just £61 million from the private sector.
"The large number of properties at significant, and in some cases increasing, risk of flooding means that prioritising spend on flood defences is essential if the UK is to minimise potentially huge costs of future flood events," it said.
"We are concerned that Defra's requirement to find reductions of 15% in resource budgets over the next four years may affect vital flood protection work."
The committee chairman, Neil Parish, said: "We welcome Defra's commitment to a six-year capital flood defence programme and its pledge to protect maintenance funding for activities such as river dredging.
"This is prudent investment since flood damage may cost more to repair than to prevent. But the increasing risk of more extreme flood events will stretch these budgets thinly."
A Defra spokeswoman said: "We are investing £2.3 billion on new flood defences over the next six years which is a real terms increase on the £1.7 billion spent in the last Parliament.
"In addition we are raising a further £600 million in partnership funding. We have made significant progress with £250 million already secured and we have identified sources for the remaining £350 million.
"We are exceeding our manifesto commitment by building 1,500 new flood defence schemes that will better protect 300,000 more homes."