Labour leader Jeremy Corbyn has praised Environment Agency staff for their "superhuman efforts" to protect homes and businesses from floods.
He said the Government must now look again at the cuts it has imposed on the agency and he called for more spending on flood defences up and down the country.
He was visiting York which flooded on Boxing Day, explaining he had not come sooner as he had not wanted to get in the way at what was a "critical time" for the emergency services.
Mr Corbyn met EA staff at the Foss Barrier, which was knocked out by flooding, to see if lessons could be learned.
He said: "We have got a lot of very hard-working engineers and workers for the EA who have made superhuman efforts to try to protect this city, as they have tried to protect other cities all around the country, and I think we should be grateful to them for that."
Asked what Labour would do to help, he said they will pressurise the Government to "fully fund the Environment Agency, not cut its budget" and pay for flood defences where necessary.
He said the flood response showed how well organisations like the EA, local authorities, the police, fire service and the army could work together, but they needed public support and funding.
When he was asked why it had taken him five days to come to York, he said: "I didn't want to get in the way of people doing an emergency job at a highly critical time.
"I think to turn up in the midst of all that is distracting engineers."
He refused to criticise the EA chairman Sir Philip Dilley who was in Barbados during the floods, saying engineers were the ones dealing with the situation.
After Storm Frank passed through the UK, the clean-up began.
In Scotland 12 people, including two children, were rescued from a bus after it was stranded in flood water on Wednesday.
Ten passengers were airlifted by a Royal Navy helicopter from the vehicle when it became stuck in Dailly, South Ayrshire, at about 1.35pm on Wednesday.
A further two people were taken off the bus by officers from Police Scotland's marine unit.
Flood waters also affected the village of Ballater in Aberdeenshire near Balmoral Castle, the Queen's summer residence.
Police arrested a 40-year-old man on suspicion of theft after residents concerned about looting from flooded homes raised the alarm.
West Yorkshire Police officers responded to reports in the Mytholmroyd area about a man acting suspiciously near wrecked properties on Wednesday morning.