British Prime Minister David Cameron has said he is "very sorry" for the suffering caused by the extreme weather afflicting large swathes of Britain.

He has promised to do "whatever it takes" to help those affected.

Mr Cameron was speaking as communities across Britain braced themselves for a battering by heavy wind, rain and even snow as Valentine's Day storms wreak havoc.

Forecasters warned that the appalling conditions, which have ravaged communities, show no signs of abating, with heavy rain expected today and tomorrow.

The Met Office has that warned wind, rain and snow is expected to strike in a "multi-pronged attack" with up to 40mm of rain set to fall in just six hours while gusts of up to 130km/h blast through parts of the country.

The Environment Agency (EA) has 17 severe flood warnings - which mean a risk to life - in place in the Thames Valley, Somerset and Gloucestershire, as well as 131 flood warnings across England and Wales and 246 flood alerts.

As well as surface water problems, the rain could also impact on already full-to-bursting rivers while some coastal areas could be at risk as blustery conditions could bring large waves.

Visiting Blackpool in Lancashire to view relief efforts, Mr Cameron told ITV1's Daybreak: "People need to be reassured that we will do whatever it takes to help people during this very difficult time."

Asked whether he would repeat Communities Secretary Eric Pickles' apology for the government's early response to the crisis, Mr Cameron said: "Of course I am very sorry for any way that people have suffered.

"What we have tried to do is stand up the emergency response arrangements as quickly as we could."

Mr Cameron said that the government's Cobra emergency committee had met before Christmas to deal with the impact of the tidal surge on the east coast and soon after Christmas as the Somerset Levels were flooded.

"Obviously, we are facing a very difficult time because we have got the wettest start to the year for 250 years and these are extraordinary weather events, but we are fighting on every front to help people," he said.

"We have deployed the military, we have got thousands of sandbags being put around people's houses, over 300,000 people had their electricity reconnected last night.

"If you look at the state of our flood defences, over 1.3 million homes have been protected by the flood defences that are in place.

"We are making sure that today, before the next rise in the level of the Thames over the weekend, we do everything we can to protect more homes and protect more communities."