David Cameron has warned that the flooding crisis in the UK is likely to get worse after weeks of winter storms and heavy rain.The Prime Minister said while the weather was due to improve, the sheer volume of rain over recent weeks means groundwater levels will continue to rise in many places.

The comments come as energy firms struggled to reconnect tens of thousands of homes after the latest strong winds and downpours.

Three people have been killed in the recent storms – an elderly passenger on a cruise ship in the English Channel, minicab driver Julie Sillitoe whose car was hit by falling masonry in London and a 65-year-old man in West Cork, Ireland, who was hit by a pole while repairing damage for a phone company.

Despite forecasts 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.

The EA has issued 16 severe flood warnings – mostly in the Southeast – and nearly 150 lesser flood warnings across the UK.

Mr Cameron, who visited flood-hit Chertsey in Surrey before chairing the Government’s COBRA meeting on Saturday evening, said the next 24 hours will be “vital” as river levels rise again.

He said: “Thankfully, it does appear that we will see less rain and wind over the next few days.

“However, after so much rain over recent weeks, groundwater levels remain very high and in many places will continue to rise.”

The EA said on Saturday the Thames Barrier had been closed for a record 16th consecutive time to help lower river levels.

Paul Leinster, chief executive of the EA, said: “We continue to see the very real and devastating impacts that flooding can have on communities and business.

“We know the distress that flooding can cause and are doing everything we can to reduce the impacts.

“Despite an improving forecast the risk of flooding will continue for many communities in southern parts of England over the next few days. We ask people to remain vigilant and take action where necessary.”

On Saturday, a 20ft deep sinkhole opened up beneath a house in Hemel Hempstead, Hertfordshire, forcing people to evacuate people living nearby.

The Met Office has issued yellow “be aware” warnings for icy driving conditions in much of the UK on Sunday. The south of England, Wales and the Midlands are also warned to expect heavy rain.

The Ministry of Defence (MoD) said more than 3,000 service personnel are committed to helping the flood relief effort, with “thousands more at a state of high readiness”.

Around 100 soldiers from the 1st Battalion The Royal Regiment of Fusiliers are still in Wraysbury, Berkshire, while more than 300 military personnel remain in Windsor, Datchet and Bisham.

Kent Police said properties remained at risk of flooding in Yalding, Collier Street, East Peckham, Kingston, Patrixbourne, Elham, Bridge, Littlebourne, Bishopsbourne, Wickhambreaux, Lydd, and from Wye to Ashford.

The Energy Networks Association said the number of homes without power had fallen to less than 30,000 on Saturday night.

Network Rail said the storm on Friday brought down more than 150 trees across the south of England, with train services in the west the worst affected.