The former England manager was involved in the campaign to abolish the £20-a-week maximum wage - something the Professional Footballers' Association, led by Jimmy Hill, managed to achieve in 1961.

And Venables admits he has been infuriated by the Manchester United winger's reported desire to secure a 'dream' transfer to Real, and in particular Ronaldo's agreement with FIFA president Sepp Blatter's claim that he is the victim of 'modern slavery'.

"What Ronaldo is doing completely cuts through the principles we fought for. And it hurts," Venables wrote in The Sun.

"Not one of us ever imagined players could be given a contract and then be free to walk away at a whim, no matter how many years were still remaining. We wouldn't have dreamt of asking for such a thing.

"Ronaldo has four years left on a highly lucrative deal that he was overjoyed to sign 15 months ago.

"What on earth gives him the right, now, to just throw it in the air and say 'I've had enough, I'm off'?

"It's selfish, it's immoral, it's potentially devastating for the game as a whole. It's wrong. And it's only any good for Ronaldo."

United boss Sir Alex Ferguson appeared to put an end to the Ronaldo transfer saga last night when he insisted the Portugal international would remain at Old Trafford.