The embattled chief of the Environment Agency has blamed Treasury funding rules for the failure to dredge rivers.
Lord Smith, a former Labour minister, said the agency had only been able to allocate £400,000 to the dredging fund last year for the Somerset Levels.
However, he insisted the government and other funding organisations had not pledged the rest of the money, estimated at £4m, to allow the dredging work to go ahead.
The unde- fire quango boss said money was “absolutely a big part of the issue”.
“In Somerset the maximum we were allowed under those rules was £400,000,” Lord Smith told the BBC’s Radio 4 Today programme.
“A year ago we put the maximum we could on the table and said here it is and now we need other people to come to the table as well. That did not happen. We were not allowed to do the full dredging…”
Lord Smith said the EA was bound by government rules that set out how much it could spend on any individual flood defence scheme.
Under Treasury rules, for every £1 spent the calculation had to determine a cost benefit of £8 to the taxpayer to contribute to any scheme.
But he added: “The situation has now completely changed, because not only has the government come up with extra money for dredging, but the Treasury has also said the rules will not apply to the Somerset Levels.”
Lord Smith also hit back at criticism from communities secretary Eric Pickles, who said the Environment Agency had “made a mistake” and should have dredged the rivers on the Somerset Levels.
“When I hear someone criticising the expertise and professionalism of my staff in the Environment Agency, who know more about flood risk management – 100 times more about flood risk management – than any other politician ever does, I am not, I’m afraid, going to sit idly by,” he said.
Lord Smith said he had been in text conversation with DEFRA secretary Owen Paterson, who is recovering in hospital from an emergency eye operation, about the flooding crisis.
He said Mr Paterson has been “hugely supportive” of the Environment Agency and its staff and its response to the record-breaking rain and flood crisis, which is on course to become the wettest winter in England since 1766.
The intensifying political row comes as farmers across the country are donating feed and forage to flooded farmers in Somerset.
With more wet weather forecast this week, 16 severe flood warnings were in place on Monday (10 February), including 14 in Berkshire and Surrey and two in Somerset.
Significant groundwater flooding is also expected in the coming days in Hampshire, Kent and parts of London.
Paul Leinster, chief executive of the Environment Agency, said: “Our hearts and sincere sympathy go out to those who have already experienced the dreadful aftermath of flooding. Our teams will continue to work around the clock to protect lives, homes, businesses, communities and farmland over the coming days.
“Extreme weather will continue to threaten communities this week, with further severe flooding expected Monday evening into Tuesday along the Thames in Berkshire and Surrey.
“River levels are high across south-west, central and southern England and further rain has the potential to cause significant flooding. I urge the public to sign up to receive free flood warnings, check their flood risk and keep up to date with the latest situation on the Environment Agency website and on social media using #floodaware.”