Lottery bosses have called Shaw House - rumoured to be where Charles I evaded an assassination attempt by a Cromwellian sniper in 1644 - a national treasure.

The building was last used as a comprehensive school until it was boarded up 20 years ago for breaching tough health and safety laws. Since then, the building has been left empty.

The £4m handout will be added to £1m from Vodafone and £1m from council coffers, but when restored, West Berkshire Council will move its registrar there for weddings and baby-naming ceremonies.

Michael Houghton, Heritage Lottery Fund Regional Manager said: "It's marvellous to see that Shaw House will be put back to use again by the public. It's always sad for the community when a building they love stands empty for so long, so it's good to know that the people of Newbury will see Shaw House restored to its former glory and made part of their lives again."

Councillors also want to hold summer concerts there, but some of the grounds are coveted by next door neighbour Trinity School, and the whole deal could collapse unless Trinity gets the nod next month to sell land for housing, so it can build a new sports hall - despite strong local opposition.

The council is now planning another lottery bid to repair the leaky roof and bowing walls of the Granary building in the wharf - where the town’s historic treasures are held for safekeeping. Meanwhile, Newbury Town Council is putting together a £750,000 lottery bid to revamp Victoria Park, although it is very rare for the Heritage Lottery Fund to support so many bids for one town.