Exclusive: The BBC will today begin work to restore a controversial sculpture outside of its London headquarters after it was vandalized by a hammer-wielding protester last year.

The 91-year-old Eric Gill artwork that adorns Broadcasting House depicts Prospero and Ariel from Shakespeare’s The Tempest, but it was attacked last year amid calls for it to be removed.

Campaigners demanded action after extracts from Gill’s private diaries, published nearly half a century after his death in 1940, revealed that he sexually abused his daughters.

The BBC declined to cave to the demands, saying it was right to have debates about whether works of art can be divorced from their creators.

It has now begun repair work, which will likely cost between £10,000 and £20,000. It will be funded by insurance, rather than through the license fee.

Scaffolding will go up around the BBC’s premises today and the work is expected to...