AMBITIOUS plans to redevelop the Bodleian Library in Oxford will have to be put on hold if its new book depository does not get the go-ahead.

Last week, Julian Blackwell, president of Blackwell's, donated £5m towards the redevelopment of the New Bodleian, in Broad Street, next door to the firm's flagship bookshop.

But the renovation project, expected to start in 2010 and finish in 2012, will only happen if the Bodleian can free up some space in the 400-year-old library by building a £29m book depository at Osney Mead.

In November, city councillors turned down plans for the depository in Osney Mead and a planning inquiry is expected to decide the issue in May, after the Bodleian appealed against the council's decision.

Richard Ovenden, keeper of special collections at the Bodleian, said he was keen to put more of the library's treasures on public display.

But he warned that the renovation project would only be possible if the library was able to address its storage problems by constructing the new depository.

He said: "We want to show off our treasures - we had 1,000 people here when we displayed our Magna Cartas and we had to turn 400 people away.

"We want to triple our exhibition space so schoolchildren and other members of the public can engage with some of the treasures that are stored here.

"But these plans are dependent on us solving our storage issues - I am confident we will be able to do that.

"The city councillors put the contents of the New Bodleian in jeopardy when they made that decision to refuse planning permission."

Mr Ovenden said the redevelopment plans were at a very early stage, although "dialogue" had taken place with the city council and English Heritage.

As part of the plans to be funded by Mr Blackwell's donation, there will be an atrium with a glass front to Broad Street and a café.

It will lead to rooms housing permanent public exhibitions, including four original versions of the Magna Carta, nearly a quarter of the world's surviving copies.

Bodley's librarian, Dr Sarah Thomas, said: "Julian Blackwell's gift will help transform the New Bodleian from a book fortress into an inviting and inspiring space for readers.

"The Blackwell Hall will welcome visitors to exhibitions and events that celebrate the book, and will serve as the entrance to the New Bodleian for those doing advanced scholarly research."

The Blackwell family's association with the Bodleian dates back many years.

In December, 2006, Julian Blackwell donated his father's collection of rare books, begun by Sir Basil Blackwell in the 1920s.

Mr Blackwell said: "The Bodleian is unique - it not only has the largest and most important university collections in the world, but it is leading the development of cutting-edge information services which are so vital to academic research."

John Goddard, leader of the city council, said: "I warmly welcome the proposal to make the New Bodleian, and the treasures of the university's libraries, accessible to Oxford residents and the public at large."

The Bodleian's collections include the papers of six British prime ministers, a Gutenberg bible, JRR Tolkien papers, a quarter of the world's original copies of the Magna Carta, and more than 10,000 medieval manuscripts.

Debbie Dance, spokesman for the Oxford Preservation Trust, said she was "hugely supportive" of the Bodleian's latest proposals, but was disappointed that the library was appealing over the book depository.