The track Now And Then, featuring performances from all four of the group's members, is set to be released at 2pm on Thursday, with a music video to follow on Friday.

The song was originally written and recorded by John Lennon in the late 1970s in his New York home. The late star's demo version featured him singing and playing the piano.

After Lennon's murder in 1980 aged 40, his wife Yoko Ono gave the tape to the rest of the band, along with rough recordings of Free As A Bird and Real Love, which were reworked and released in the mid-1990s.

The group's surviving members, including George Harrison, also worked on Now and Then during the sessions.

However, they ended up not releasing the song due to problems trying to clearly extract Lennon's vocals and piano from his demo because of limited technology at the time.

Harrison died in November 2001 aged 58.

Now, new audio restoration technology has allowed Lennon's original demo to be cleaned up and used, alongside Harrison's electric and acoustic guitar recordings for the song in 1995.

Backing vocals from The Beatles tracks Here, There And Everywhere, Eleanor Rigby and Because have also been added.

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New versions of two of the band's greatest hits compilation albums will also be released on 10 November.

The so-called The Red Album, featuring songs from 1962 to 1966, and The Blue Album, covering the period from 1967 to 1970, have been updated and will feature some newly-remixed tracks.

A documentary about the new song, Now And Then - The Last Beatles Song, is also set to premiere at 7.30pm on Wednesday on The Beatles YouTube channel.

Sir Paul McCartney said it was "exciting" to be working on new Beatles music in 2023.

Speaking previously about the project, he said: "There it was, John's voice, crystal clear. It's quite emotional and we all play on it, it's a genuine Beatles recording.

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"In 2023, to still be working on Beatles music, and about to release a new song the public haven't heard, I think it's an exciting thing."

Meanwhile, Sir Ringo Starr said: "It was the closest we'll ever come to having [Lennon] back in the room so it was very emotional for all of us. It was like John was there, you know. It's far out."