Michael Bublé gives an incredibly moving performance following his son's cancer diagnosis

Viewers of the Children in Need live appeal were left in tears after Michael Buble's heart-breaking performance of God Only Knows, just weeks after it was confirmed that his son Noah, three, was battling cancer.

The couple released a statement saying they would be “putting their careers on hold” while Noah received treatment, with Buble reportedly vowing to not sing again until his son had beaten the disease.

However, the crooner made one last appearance on the televised charity fundraiser, performing a pre-recorded rendition of the Beach Boys' hit.

The 41 year-old recorded the song for the children's charity back in October, before his son was diagnosed with cancer.

Many took to Twitter to comment on his rendition of 1966 classic, with one person posting: "Michael Bublé is an absolute legend for doing this #MichaelBuble #ChildrenInNeed."

Another person wrote: "Hats off to Michael Buble, what a strong man! You can see the pain written all over his face, heart-breaking to see #ChildrenInNeed."

Two others agreed: "@michaelbuble had me in bits on #ChildrenInNeed tonight. Could see how hard it was for you to sing that song tonight. Kudos," and: "Just watched @michaelbuble on #ChildrenInNeed. Such a moving performance given what he's going through. Every respect to him."