Evidence suggests climate change played a part in Cumbria floods - Met Office
The Met Office has warned that "all the evidence" suggests climate change played a role in the floods which have devastated thousands of homes following Storm Desmond.
Record amounts of rain have fallen in Cumbria, the worst-hit county, where many residents were evacuated and tens of thousands of properties left without power.
The Environment Agency said more than 5,200 homes and businesses were flooded, with Prime Minister David Cameron visiting the worst-hit areas.
The Met Office has issued a severe weather warning for rain this week as northern England, Scotland and Northern Ireland brace themselves for more heavy downpours.
Environment Secretary Liz Truss said there had been a "number of weather-related fatalities" and the severity of the weather was "unprecedented".
A body thought to be that of an elderly man was discovered in the swollen River Kent in Cumbria, and a 90-year-old man, Ernie Crouch, died after he was apparently blown into the side of a moving bus by strong winds near Finchley Central Tube station in London.
The Met Office said a new record had been set for rainfall over a 48-hour period, with 15.9in (405mm) falling in 38 hours at Thirlmere in Cumbria.
A 24-hour record was also recorded between Friday and Saturday evenings, with 13.4in (341mm) registered in Honister, Cumbria - more than a month's worth of rain in one day.
The Met Office's chief scientist Dame Julia Slingo said the extreme weather conditions were "extraordinary".
She told BBC Radio 4's World At One: "Is it to do with climate change? There can't yet be a definitive answer but we know that all the evidence from fundamental physics and what we understand about our weather patterns, that there is potentially a role."
Disruption caused by the storm looks set to continue, with many roads closed and the West Coast Mainline rail route to Scotland suspended with service unlikely to be restored before Wednesday at the earliest.
Electricity North West said 61,000 properties lost power across Heysham, Morecambe, Carnforth and Lancaster.
Meanwhile, Lancaster University confirmed it had cancelled a ll classes until the new year as a result of floods.
The Government said it will "look again" at flood defences amid mounting criticism that they failed to keep the deluge of water out of people's homes.
Speaking in Carlisle, Mr Cameron admitted the multimillion-pound barriers built following devastating floods in 2005 "weren't enough on this occasion".
Forty-six severe flood warnings were in place, meaning a danger to life, across the North West, along with dozens of less serious flood warnings and flood alerts over northern England and Wales.
Cumbria Police said up to 6,425 properties might have been flooded in the county but the most likely scenario was that 4,881 had been affected.
Some 2,685 properties in Cumbria remain without power, the force said.
In Carlisle, the Army was sent to help support emergency services evacuating people from their homes in streets where cars were almost entirely submerged.
Around 40 schools remained closed in Cumbria, while the disruption led to the cancellation of appointments and routine business across NHS hospitals and services.
Power has been restored to all homes in North Wales after heavy rain and wind left 700 without power on Saturday, and in Northern Ireland, major clean-up operations are under way in parts of counties Tyrone and Fermanagh after weekend flooding damaged homes and businesses.
An appeal by Cumbria Community Foundation to raise £1 million to support vulnerable individuals and families who have been badly affected by the floods is under way and has already raised more than £300,000.
Ms Truss told MPs that the Bellwin scheme allowing councils to recover the costs of tackling floods from Whitehall would be put into operation and further support schemes would be announced over coming days. The Government has already committed to a £2.3 billion programme of flood defences over six years.
Bridge inspections have been ongoing throughout the day with several reopened but a total of 130 in the county still need immediate checks, said Cumbria County Council.
Military engineers are assisting to speed up the process with the council drawing up a full programme of inspections for all the remaining 1,500 bridges over the coming days and weeks.
All road bridges in Kendal are now open, while the Cocker Bridge in Cockermouth is also open but not the Derwent Bridge.
The Jubilee footbridge in Appleby is accessible but the main bridge across the River Eden remains closed and requires underwater inspection.
A number of other bridges remain underwater and closed, added the council.
Several roads have sustained extensive and significant damage including the A591 in Thirlmere, the A592 in Ullswater and A686 at Langwathby.
Military personnel are also providing support to communities in Patterdale and Glenridding which have been cut off.
A council spokesman said: "This level of damage is unprecedented and we have had staff working flat out to assess the scale of what's happened and begin to put plans in place. It's still dangerous out on the road network and we're urging people to stay away from closed bridges and damaged roads, it's possible there could be further subsidence or collapse."
Virgin Trains said Lancaster station had been closed due to a lack of power and bus replacements were in place.
Labour leader Jeremy Corbyn accused the Government of failing in its efforts to tackle flood defences.
Speaking from the Trade Unions for Energy Democracy meeting in Paris, he said: "Last year, the Prime Minister of Britain promised that 'money is no object' in dealing with flooding, itself a consequence of the destruction of our environment.
"But this has proved to be yet another false promise. In the last parliament, the Government slashed spending on flood defences before the 2014 winter floods.
"The Government has failed to deliver on their promises. They have abandoned the consensus on flood investment built by the Labour party after the 2007 floods - and are failing the British people because of their obsession with austerity."
A further loss of power supply to 42,000 homes and businesses in Lancaster, Morecambe and Carnforth took place at 4pm due to "unforeseen flood damage" at a substation in Lancaster, said Electricity North West.
Its engineers plan to begin restoring the supplies from 8am tomorrow.
A toal of 2,657 properties remain without power in Cumbria, where floodwater is restricting access for Electricity North West teams, added the firm.
Flood defences at its Kendal and Carlisle substations have held, protecting supplies to 110,000 homes.
Mark Williamson, operations director for Electricity North West, said: "Unfortunately power was lost to customers in Lancaster and the surrounding areas this evening due to unforeseen flood damage at our substation. "We plan to begin to restore supplies from the substation tomorrow morning and we would like to thank our customers for their patience and support during what continues to be an enormously challenging time for everyone involved."
Some 19,000 customers in Lancaster are still being supplied by generators that were mobilised on Sunday night, with further generators to be mobilised overnight.
Electricity North West said its engineers had restored power to a further 1,200 customers in Cumbria, with more than 1,450 - the vast majority in Carlisle - remaining without.