Thousands of people remain without power in the aftermath of serious flooding following Storm Desmond.
Homes and businesses have been devastated by record rainfall, and the extreme weather has claimed three lives.
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.
Engineers will begin restoring power to 42,000 homes and businesses in Lancaster, Morecambe and Carnforth from 8am, after "unforeseen flood damage" at a substation in Lancaster caused them to lose supply on Monday.
Some 19,000 customers in Lancaster are still being supplied by generators that were mobilised on Sunday night, and further generators were being mobilised overnight.
While a further 1,200 customers in Cumbria - the worst hit county - have had power restored, more than 1,450, the vast majority in Carlisle, remain without.
The Environment Agency said more than 5,200 homes and businesses were flooded, with Prime Minister David Cameron visiting the worst-hit areas.
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, while Irish police recovered the body of Ivan Vaughan, 70, in Co Monaghan.
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 on Saturday.
The Met Office warned that "all the evidence" suggests climate change played a role in the floods, with chief scientist Dame Julia Slingo describing the extreme weather conditions as "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."
A new record was set for rainfall over a 48-hour period, with 15.9in (405mm) falling in 38 hours at Thirlmere in Cumbria, while 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.
Ms Truss said the Bellwin scheme allowing councils to recover the costs of tackling floods from Whitehall will be put into operation and further support schemes are to be announced over coming days.
In the face of mounting criticism that it failed to keep the deluge of water out of people's homes, the Government said it will "look again" at flood defences.
Labour leader Jeremy Corbyn accused the Government of making "yet another false promise" on flood defence spending.
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."
Spending on flood defences in England is due to fall by 14% this year.
The Government has set aside £695 million for dealing with flooding and erosion in 2015/16 - £116 million less than in 2014/15, according to figures from the Department for Environment, Food and Rural Affairs, and is the biggest year-on-year fall since 2011/12.
Speaking in Carlisle, Mr Cameron admitted the multimillion-pound barriers built following devastating floods in 2005 "weren't enough on this occasion".
Electricity North West said flood defences at its Kendal and Carlisle substations have held, protecting supplies to 110,000 homes.
Cumbria County Council said military engineers are assisting to speed up the process of bridge inspections with a full programme of inspections for all the remaining 1,500 bridges over the coming days and weeks.