THE first iron bridge built by pre-eminent British engineer Isambard Kingdom Brunel is to be reconstructed near to where it was discovered two years ago under a new plan.

The 166-year-old bridge over the Grand Union Canal, near Paddington Station, was scheduled for destruction to make way for a new road crossing until details of the bridge's designer were uncovered by chance in March 2004.

Leafing through Brunel's surviving notebooks, a historian found designs and a record of load-testing for the cast-iron beams of a Paddington canal bridge, dating from 1838.

The unique structure was hidden for decades within a modern brick road bridge. It was removed from the larger structure it was concealed in and has been stored in Portsmouth until the £3.5m needed to restore it is raised to rebuild it as a footbridge.

It is the earliest of only ten surviving Brunel iron bridges in the country.

He is best known for the network of railway tunnels and various bridges he built including the famous Clifton Suspension Bridge in Bristol.

Roger Hanbury, chief executive of The Waterways Trust, said: "These exciting plans for the restoration of this historic masterpiece give it the place and prominence it deserves. However, before we can go ahead with the restoration we need raise the £3million required otherwise the bridge will remain cut off from public access and its home in Paddington."

Dr Steven Brindle, English Heritage inspector of Ancient Monuments, added: "We were very lucky to find Brunel's historic masterpiece, just in time to prevent it being demolished: saving the bridge was a great collaborative effort by many partners, and rebuilding it will have to be as well.

"This year sees the bicentenary of Brunel's birth in 1806, and there could be no better way to mark this occasion than by initiating the campaign to rebuild this, his earliest surviving iron bridge, at this most appropriate site on the Harrow Road, so close to its original site and to Paddington Station.

"This is the earliest of maybe ten iron bridges by Brunel to survive its design is unique and it represents a turning point in Brunel's thinking, in particular in his structural use of iron. "