Manchester United will suspend Cristiano Ronaldo without pay - if he carries out a threat to go on strike.

Old Trafford bosses will get tough in their fight to keep the Portuguese boy wonder out of the clutches of Real Madrid.

Claims from Madrid that Ronaldo will go on strike to force his £70million move to the Bernabeu sparked a damning response from Old Trafford. A United source said: "If Cristiano decides to go on strike the club would have no hesitation in suspending him and stopping his wages with immediate effect.

"We hope it won't come to this."

Ronaldo is just 15 months into a five year contract worth £120,000 a-week.

United are well aware Real are offering him terms that will shatter his current deal. Claims that United boss Sir Alex Ferguson would fly to Portugal's Euro 2008 camp this week for talks with Ronaldo are untrue.

But he has tried to contact the double Footballer of the Year by telephone and been blanked. And it's not just Fergie Ronaldo has avoided. He has refused to respond to a deluge of calls from anxious United teammates all pressing him to end the speculation by saying he will stay.

United are also set to report Real to FIFA this week for their persistent illegal approaches for Ronaldo. Gabriel Heinze (right), the former United star who moved to Real last year, added to the debate yesterday as he said: "I don't think Ronaldo will get any better as a footballer. He's already next to God in his ability!

"If I had to pay for one player I would choose him.

"In Madrid we'd welcome him with open arms. I don't think he'd have problems adapting to any team in the world. Players of his quality fit in anywhere."

Some United insiders believe Ronaldo would not have the backbone to go on strike. But reports in Madrid over the past week insisted that Real could do no more to get him out.