It is now known that 263 seal pups have been lost from the beach at Horsey Gap, where the National Trust has offered support to the Friends of Horsey Seals, who manage the monitoring of the colony.

A National Trust spokesman said: 'Our staff share the sadness many people may feel about the impact on the seal colonies. It is now imperative that we allow these wild animals to respond to this natural event and for the remaining pups to be found by and reunited with their mothers.

'Any human interference at this stage could be very damaging to the remaining seals and pups.

'We strongly urge that if visitors to the Norfolk coast come across any seals or pups in the aftermath of the tidal surge, please, do not attempt to move them or encourage them to return to the sea. The pups are safer on land until they shed their distinctive white fur.'

National Trust ranger teams were unable to assess the impact to the seal colony at Blakeney National Nature Reserve, because it was impossible to access Blakeney Point.

Grey seals begin arriving at Horsey beach every November, giving birth over two or three months before leaving in late January or February.

For the first few weeks of their lives, grey seals pups cannot swim as they are born covered in white fur which is not waterproof. As they grow, feeding on about three litres of their mother's milk a day, they shed their fur and soon head into the water for fish for themselves.

In the past decade, the number of seals born on Horsey has risen from about six to about 600 in 2012/13 and now, every festive season, thousands of people head to the beach to see the animals in the wild.