More than 7000 British troops have been called in to the north of England which has been hit with "unprecedented" levels of rain.
Thousands of homes in York have been evacuated after heavy rain caused the Foss and Ouse rivers to burst their banks. The city's flood barrier has also been raised, Sky News reports.
It has also left more than 7000 homes without power.
UK Prime Minister David Cameron is set to visit the heavily flood-hit areas today (local time).
He earlier chaired an emergency meeting to discuss the response to the flooding which has affected York, Leeds and Lancashire.
"We'll do everything we can to help people in their hour of need," he said.
Environment secretary Liz Truss says the downpour "overwhelmed" the flood defences which will now need to be reviewed.
Dozens of severe flood warnings are still in place in Yorkshire and the North East.
Engineers are working to restore power to more than 7500 homes in Greater Manchester and Lancashire.