David Cameron has warned that the flooding crisis is likely to get worse even though Britain is set for a respite from the winter storms.
The Prime Minister said while the weather was due to improve, the sheer volume of rain over recent weeks meant groundwater levels would keep rising in places.
The comments came as power firms struggled to reconnect homes after the latest downpours.
Despite weather forecasters predicting an "improving picture" with lighter winds and less rain, the Environment Agency (EA) said parts of southern, south west and central England remain at risk of flooding.
Mr Cameron, who visited flood-hit Chertsey in Surrey before chairing the Government's Cobra emergency committee this evening, said the next 24 hours would be "vital" as river levels were set to rise again.
"Thankfully, it does appear that we will see less rain and wind over the next few days," he said."However, after so much rain over recent weeks, groundwater levels remain very high and in many places will continue to rise."
The EA said it had closed the Thames Barrier for a record 16th consecutive time to help lower river levels.
Yellow "be aware" weather warnings of icy driving conditions are now in place for most of the UK. Across the south of England, there are also warnings of heavy rain.