Sir Elton John will ''never'' stop performing, according to husband David Furnish.

The 'Rocket Man' hitmaker's 55-year-old partner - who have sons Zachary, six, and Elijah, four, together - has insisted the 70-year-old music legend will never quit the music business because retirement would feel like ''purgatory'' to the icon.

Speaking about his lover and his career, the filmmaker - who is also Elton's manager and CEO of Rocket Entertainment - said: ''Without question, Elton must never stop performing. We all have things that kind of keep us alive in life. Some people relish the idea of a retirement where they do nothing [but] for Elton that would be purgatory. Playing to live audiences is going to be something he always needs to do.''

And David has revealed Elton is ''very proud'' of his legacy, and his ''passion'' for penning new tracks ''keeps him alive''.

He continued: ''He takes his legacy very seriously and he's very proud of it, but the most important thing for Elton is that he continues to look forward, he's never going to stop. I think the passion the keeps him alive is that he needs to continue to create and write, he needs to collaborate.

''The most important thing with Elton is that he stays connected, both in terms of people being able to discover his music and to keep his music alive and also in terms of being able to discover new artists.''

And the 'It's A Boy Girl Thing' producer has hailed the 'Tiny Dancer' hitmaker for his knowledge of the music business, as he believes Elton knows ''more'' about the industry than any ''average record company executive''.

He said: ''I actually think Elton knows more about the music business than the average record company executive. He gets all the charts and the new releases for most of the major markets every week. He still gets them by fax which is going to be a problem in about a year's time when we're not going to be able to put faxes down digital phone lines any more. He follows and tracks and charts everything, he knows exactly when a record's going to break, why it's going to break, where it's not getting enough push, play or promotion, he's a real anorak when it comes to stats, sales figures, numbers and he's able to retain them and process an enormous amount of data. That structure in his life helps to keep him grounded and keep him connected with the greatest passion in his life, which is music. So yeah, he's very plugged into what's going on -- it's kind of spooky!''

And Elton has no plan to slow down as a ''live action musical fantasy'' production of his life, which will be titled 'Rocket Man', is in the works and slated for release in 2018.

David told Music Week magazine: ''He's going to wind down his residency in Las Vegas, so he's got another run in February and then another run in May. We're going to be shooting a live action musical fantasy version of Elton's life story called 'Rocket Man', that's going to go into production next year.

''He's also working on his memoirs and then we have a few surprises up our sleeve.''