The 23-year-old scored 41 goals as United retained the Barclays Premier League and reached Wednesday's Champions League final, but his efforts have made the forward one of the hottest properties in world football.

Charlton told the Mail on Sunday: "Ronaldo's on a long-term contract with us. I don't have to say we expect him to honour it because he will honour it unless something tragic happens. Do I think Ronaldo will be at United next season? Absolutely."

He added: "It really irritates me how people can set rumours going and undermine people through the media. It's unethical.

"They have not got the right to undermine the way we have helped this lad.

"Everybody seems to think that Real Madrid or Barcelona are the two greatest clubs in the world. I don't think I have to tell Cristiano that Manchester United is the biggest club in the world."