David Cameron has described the recent severe flooding as a "tragedy" for all those affected and warned further rain in the week ahead would fall on already saturated ground.
Speaking after chairing a meeting of the Government's emergency Cobra committee, the Prime Minister highlighted the "extensive efforts" under way to protect and repair properties and transport links.
He also praised all those involved in the response to the crisis.
It came amid a fresh warning that communities could face further misery from rising water levels with more rain forecast.
Severe flood warnings remain in place along the Thames and in Somerset.
Meanwhile, Defence Secretary Philip Hammond admitted the military could have been brought in earlier to help deal with the winter storms that have wrought havoc across the country and claimed a number of lives.
Two people died on Friday - James Swinstead, 85, an elderly passenger on a cruise ship in the English Channel, and minicab driver Julie Sillitoe, 49, whose car was hit by falling masonry in central London.
A 65-year-old man in West Cork, Ireland, was killed after being hit by a pole while repairing damage for a phone company.
A 20-year-old pregnant woman and her unborn baby, from Tredegar, South Wales, also died in a crash on the A465 between Brynmawr and Garnlydan.
The Government has now deployed more than 3,000 troops to help with flood relief and made 5,000 more available if needed.
David Cameron also unveiled a £10m Business Support Scheme to help smaller firms with the flood clean up and to ensure they can carry on trading.
A helpline - on 0300 456 3565 - is also being set up to give advice to businesses.
The Environment Agency continues to use massive pumps to take water away from the Somerset Moorlands and some of the affected parts of the Thames Valley.
In the meantime, Thames Water has apologised to customers in the Cheltenham area who have experienced problems with their mains supply over the weekend.
The company blamed power cuts causing a pumping station to fail but said this had now been fixed.
Despite a respite in the weather, swathes of the UK remain on alert.
With the ground already saturated, there are concerns water levels will respond quickly to further rainfall.
While the rain would not be at the same level recently seen, Mr Cameron warned: "This additional rainfall will add to high groundwater levels and will impact slow feeding rivers over the days ahead."
He added: "I'm hopeful the work to strengthen long-term flood defences and the emergency measures which have been put in place over recent days and weeks will mean we can minimise the number of homes and businesses affected by the latest high water levels.
"The recent flooding has been a tragedy for all those affected and my thoughts are with them.
"While it is of no comfort to those individuals, over 1.3 million other homes have been protected since December and we'll continue to invest in flood defence measures to protect even more.
"Extensive efforts to protect and repair properties and infrastructure are ongoing by many thousands of people among agencies, the military and the emergency services. I speak for us all when I thank them profusely for their hard work."
The Prime Minister also said one million homes have now had power restored.
The Thames Barrier was closed for a record 18th consecutive time on Sunday and Kent Police said properties remained at risk of flooding in many areas.
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