An 11-year-old boy was fighting for his life after being struck by lightning in storms that have deluged Britain.

The schoolboy, from Swindon in the southwest, went into cardiac arrest on Wednesday afternoon after being hit by lightning at Dorcan Academy, and received treatment from first-aiders until paramedics arrived.

"The patient had in effect been electrocuted and gone into cardiac arrest," said John Oliver, spokesman for Great Western Ambulance Service.

Oliver added that the fast response from school staff and paramedics had added to the boy's chances of survival.

Storms and heavy rain have caused flooding of homes and transport delays across the country this week, with at least 400 homes and businesses inundated.