IT consultant Stephen Hitchcock was given the collection, which originally belonged to his grandfather and then his father, at the age of 12.

The 35-year-old, from Brighton, began filling in the gaps over the next ten years, tracking down and buying the missing number ones.

Now the item, which contains everything from 78rpm, 7", 12", CD singles and digital downloads, is expected to fetch £25,000 at the Abbey Road Studios this month.

The digital tunes are stored on an iPod Nano and the collection also includes an original 1955 Pye Black Box for the 78rpm records.

The first UK number one single, Italian-American crooner Al Martino's Hear in My Heart, was bought by Mr Hitchcock's grandfather in 1952.

Every number one in the collection is an original, and comes in virtually every musical format.

Mr Hitchcock is continuing to buy number ones until the date of the Cooper Owen's Music Legends auction.

The collection contains everything from the big band hits of the 1950s and rock n' roll classics to psychedelia, disco, punk, new romantic, house and Britpop.

Mr Hitchcock, whose 2139 pieces are stored in professional DJ storage boxes, said: "I started buying first edition number ones every week and then, over the next ten years, updated the collection.

"I would love whoever buys it to continue the collection, or even better I would love it to go into a museum.

Cooper Owen Managing Director John Collins said: "This is probably the biggest collection of British popular music ever discovered.

"It gives a remarkable insight into the changing face of the industry, covering every musical format of the number one record.

"It is a real reflection of how popular British tastes in music have changed over the last 50 years and the way we listen to our music.

"Whether you're a lover of vinyl, or downloads, this is a music lover's dream.

"I've never seen anything as extensive as this with so many rare pieces. When I saw it, I was just blown away."

Cooper Owen's Music Legends Sale takes place at Abbey Road Studios on July 28.