Autobiographies by David Beckham and David Blunkett and the fourth instalment of Harry Potter are listed among books that Britons are least likely to finish reading.

The average Briton spends more than £4,000 on books during their lifetime but nearly half remain unread, according to today's study.

Surprisingly, Booker-prize winning murder mystery Vernon God Little, by DBC Pierre, topped the list of works of fiction which readers could not complete.

More than a third (35%) of those who bought or borrowed the book, a best-seller, admitted that they did not finish it.

Just under a third, (32%), of adult readers admitted they did not get to the end of Harry Potter and the Goblet of Fire.

Ulysses was third, with 28% of those who bought Irish novelist James Joyce's notoriously difficult modernist masterpiece unable to complete it.

The fiction list also includes Captain Corelli's Mandolin by Louis De Bernieres (27%), David Mitchell's Cloud Atlas (24%), which consists of six interlinked stories, and The Satanic Verses (21%) - the novel for which Salman Rushdie was issued with a fatwa.

The non-fiction list is topped by former Home Secretary David Blunkett's lengthy autobiography The Blunkett Tapes, which proved too much for 35% of readers.

Bill Clinton takes second place, losing 30% of readers before they finish the 1,024 pages of My Life.

David Beckham: My Side, which won a British Book Award for the fastest-selling autobiography of all time, is third (27%).

Other non-fiction titles include Eats, Shoots & Leaves: The Zero Tolerance Approach to Punctuation by Lynne Truss, Jade Goody's autobiography, and Allen Carr's Easy Way to Stop Smoking.

Researchers, commissioned by Teletext, who interviewed 4,000 Britons, found a fifth of all readers skip the childhood details and dive straight into the heart of biographies.

More than half, (55%), admitted they often buy books for decoration, and have no intention of actually reading them.

Books in this category include Ulysses, The Downing Street Years by Margaret Thatcher and Cloud Atlas.

The report found attention spans have shrunk in the digital age, with 42% admitting they are unable to concentrate on long-winded titles.

Many also revealed they found it difficult to dedicate time to reading for pleasure, with only 24% finding time to read every day, with most, (48%), saying they were too tired.

Teletext has provided a synopsis of the books on www.teletext.co.uk

Top ten fiction titles which Britons cannot finish:

1. Vernon God Little, DBC Pierre
2. Harry Potter and the Goblet of Fire, JK Rowling
3. Ulysses, James Joyce
4. Captain Corelli's Mandolin, Louis De Bernieres
5. Cloud Atlas, David Mitchell
6. The Satanic Verses, Salman Rushdie
7. The Alchemist, Paulo Coelho
8. War and Peace, Leo Tolstoy
9. The God of Small Things, Arundhati Roy
10. Crime and Punishment, Dostoevsky

Top ten non-fiction titles which Britons cannot finish:

1. The Blunkett Tapes, David Blunkett
2. My Life, Bill Clinton
3. My Side, David Beckham
4. Eats, Shoots & Leaves: The Zero Tolerance Approach to Punctuation, Lynne Truss
5. Wild Swans, Jung Chang
6. Allen Carr's Easy Way to Stop Smoking
7. The Downing Street Years, Margaret Thatcher
8. I Can Make You Thin, Paul McKenna
9. Jade: My Autobiography, Jade Goody
10. Why Don't Penguins' Feet Freeze?: And 114 Other Questions, Mick O'Hare