Hundreds more homes face flooding as the latest wave of winter storms lash Britain over coming days - and travellers can expect misery for months to come.
The grim predictions came as David Cameron sought to quell squabbling between ministers and the Environment Agency, ordering them to "get on with their jobs" rather than criticising each other.
The Thames Valley is due to bear the brunt of the storms this week, with the agency and emergency services working around the clock to minimise the damage. Forecasters say there is little chance of the storms easing until at least next week.
Communities Secretary Eric Pickles told MPs there was a high risk that the Thames, the Severn and the Wye would all break their banks as water levels rise.
Efforts to deal with the flooding have been overshadowed by a bitter clash between ministers and the EA, after Mr Pickles yesterday issued a barbed apology for relying on its advice.
Environment Secretary Owen Paterson - who was leading the response until being forced to undergo an eye operation - is said to have complained to Downing Street over his Tory colleague's intervention. Both ministers have played down the apparent rift, insisting they are "working closely" to respond to the crisis.
But furious EA chairman Lord Smith used a round of broadcast interviews to hit back, saying his staff know "100 times more" than any politician about flooding.
He also squarely blamed Treasury funding rules for the failure to dredge rivers.
Attempting to take the heat out of the spat this afternoon, the Prime Minister said: "I am only interested in one thing, and that is making sure that everything government can do is being done, and will go on being done to help people through this difficult time.
"This is a time for everyone to get on with the jobs that they have. This is not the time to change personnel here. This is the time to get on, do everything we can. I back the EA, I back the work they are doing.
"Everyone's got to get on with the jobs they are doing.
"There will be time later on to talk about things. Right now everybody's got to focus on the job in hand.
"That is the EA, every department in government, and let's not forget the emergency services and the army, who are doing a brilliant job."
Number 10 rejected suggestions that the Cabinet was at war, with the Prime Minister's spokesman saying: " I don't think there is a difference between Eric Pickles and Owen Paterson on this."
Asked whether Mr Cameron agreed with an unnamed Cabinet minister who was quoted as describing Mr Paterson as "stupid", the spokesman responded: "The Prime Minister's view is that Owen Paterson does an excellent job."
He denied that there had been a lack of urgency in the Government's response during the early stages of the flooding, when the emergency Cobra committee was sometimes chaired by a junior environment minister.
The spokesman said Mr Cameron associated himself with the "unreserved apology" offered yesterday by Mr Pickles, who accepted that it was a mistake to have stopped dredging rivers in the Somerset Levels.
"The Prime Minister would associate himself entirely with Eric Pickles's apology and the reason why, which is that there hasn't been the dredging that was required and that is something that is going to be put right," said the spokesman.
Mr Pickles had been expected to visit the Thames Valley this afternoon, but instead came to the Commons to answer an urgent question on the crisis tabled by Labour.
He flatly denied criticising the "marvellous workforce" at the EA and told the Opposition to stop trying to score "political points", insisting: " As I told the House on Thursday, I commend the hard work of the emergency services, local authorities, the armed services and the on-the-ground staff of the Environment Agency.
"There will be lessons to be learnt including the policy with regards to dredging and how much is spent of the £1.2 billion budget."
Mr Pickles is due to chair a Cobra meeting in London this evening, with the Prime Minister participating by phone.
Labour leader Ed Miliband said: "It is a disgrace that you have Government ministers today pointing the finger at each other when they should be rolling their sleeves up and helping those who are affected.
"The Government needs to explain why their response to the flooding has been so slow to help the victims and why their planning has been so inadequate.
"The Department of the Environment actually downgraded flooding as a key objective when the Conservatives came to power.
"But really what the public wants is a Prime Minister and a government focused on them, getting on with the job, not pointing fingers at each other or other people and trying to shut off blame."
The Met Office's Sarah Davies told a briefing that strong winds forecast for the middle of the week could add to the problems facing the country.
Some 20-40mm (0.75-1.5 inches) of rain is expected by Friday night across many southern and western areas.
But some regions, including the already flood-hit south west of England, south Wales, western Scotland and Northern Ireland could have up to 70mm (2.75 inches).
The EA's Pete Fox added: "The very latest figures suggest we have seen around 800 to 900 properties flooded since the end of last week.
"We are still looking and focusing our attention on the Thames. We urge people to look very carefully at the Environment Agency website and make sure they are signed up for free flood warnings.
"You might expect to see some hundreds of properties flooded over the course of the next two or three days."
Network Rail said disruption to lines and infrastructure could take "some months" to resolve.