Jeremy Corbyn has vowed that a Labour government would spend £5.6bn on flood defences if he wins the keys to Downing Street.
His party is pledging the new cash, to be spent over 10 years and focused on communities most exposed to flooding, as parts of the UK are left picking up the pieces from last week’s deluge.
Yorkshire and the East Midlands were hit hardest during the floods, which put the country’s readiness for extreme weather in the spotlight.
It comes as the UK prepares to go to the polls in the December 12 general election.
The Labour leader, who alongside Liberal Democrat leader Jo Swinson has sharply criticised Boris Johnson’s response to the floods as “woeful”, said the cash will come from the £250bn “green transformation fund”.
Both have urged the prime minister to declare a “national emergency” over the floods.
After Johnson chaired a meeting of the government’s emergency Cobra committee to discuss the situation, the prime minister said £2,500 would be made available to businesses affected by flooding, while an additional 100 Armed Forces personnel will be deployed to help the recovery effort.
Claiming the government’s current funding package favours the South East, Corbyn said the new floods cash will be pumped into the North West, Yorkshire and the East Midlands as a priority.
An analysis by the party says flood defence spending has fallen 15% in the North West, 14% in Yorkshire and 3% in the East Midlands between 2016 and 2018.
It also claims that, over the same period, the South East has seen a rise in spending of 14.5%.
“This last week has confirmed what we’ve seen over the last decade: the Tories always ignore the North’s needs,” Corbyn said, after visiting flooded parts of Doncaster alongside Labour candidate Caroline Flint last week.
“We need to do everything we can to help those families who have already suffered, and protect communities from further potential flooding.
“More must be done to prevent these crises from happening in the future. Every year we don’t act means higher flood waters, more homes ruined and more lives at risk due to climate change.”
Downpours last week meant several areas in Yorkshire and the East Midlands were struck by a month’s worth of rain in a single day.
The weather conditions also claimed the life of Derbyshire’s former High Sheriff Annie Hall, who was pulled from the River Derwent near Matlock on Friday.
In Fishlake, near Doncaster, about half the 700 residents left the village and those who stayed behind have faced waist-high floods.
Visiting Fishlake on Tuesday, Lib Dem leader Jo Swinson accused the government of not taking it as seriously as it should.
She added: “It should be declaring a national emergency so they can open up the ability to apply to the EU for the emergency funds that are available at times of extreme floods.
“They are not yet doing that and they should be doing that.”
The Environment Agency (EA) said it had more than 200 staff on the ground in South Yorkshire supporting communities affected by the “devastating flooding”.
Since the disaster unfolded on Thursday, some 13,500 properties have been protected by flood defences, including nearly 5,000 in South Yorkshire, while flood storage areas are also being operated to protect 7,000 homes in parts of Nottinghamshire, Derbyshire and Lincolnshire, the EA added.
But it warned the flood risk remained high, with heavier bands of rainfall expected on Thursday and Friday this week.