Cristiano Ronaldo: Seven key questions on this summer's biggest transfer story as Manchester United eye former player

We assess the latest updates on this summer's surprise transfer saga, how likely he is to leave and why the news has come out now

Ronaldo's decision to leave Madrid is 'irreversible', according to the Portuguese daily A Bola (Getty)

The summer transfer window started with its usual bluster: the rumours, the gossip, the "come-and-get-me" pleas. But then it became a hurricane.

On Friday, Portuguese daily A Bola reported that Cristiano Ronaldo wants to leave Real Madrid.

Any deal for the four time Ballon d'Or winner would surely go down as the biggest transfer in football history - far-eclipsing Paul Pogba's record-breaking move to Manchester United last summer.

So what's the latest on the summer's surprise transfer story, how likely is it to happen, and why has the news come out now?

We run through all those questions (and more) below:

What’s the latest?

Chelsea have emerged as surprise contenders for the 32-year-old's signature with the Sunday Express reporting that Roman Abramovich is willing to pay a world record fee to land him.

That figure could be in the region of 150m euros if Ronaldo's advisers are to be believed, although Real Madrid are said to be demanding at least 350m euros.

According to the Sunday Mirror, Ronaldo told Sir Alex Ferguson, his former manager at Manchester United, of his desire to leave the Spanish capital six weeks ago.

Why does he want to leave?

According to the initial reports from Portugal, Ronaldo is "deeply disillusioned" with his situation in Madrid and considers himself a "victim of persecution" by the Spanish tax authorities.

Ronaldo has been accused of defrauding the tax man to the tune of £13m - an allegation he vehemently denies.

Sources close to the payer have briefed media outlets that he wants to leave for footballing reasons. Having won three Champions League titles in the past four years as well as this season's La Liga, there is a sense that he wants a new challenge.

Has this happened before?

Yes - Ronaldo has angled for a move away from Madrid at least twice before.

The sense is that the 32-year-old feels he doesn't get the same sort of support at Madrid that his nemesis Lionel Messi receives at rivals Barcelona.

Why has the news come out now?

If Ronaldo knew he wanted to go six weeks ago, there is a chance that he delayed leaking the news until after the Champions League final.

However, it may not be as innocent as that. Some believe this to be a carefully choreographed tactic by his agent Jorge Mendes to divert the news agenda away from his tax trial.

It is also worth noting that each previous occasion Ronaldo has angled for a move before has concluded with him earning a bumper new contract in the Spanish capital...

What are the Spanish papers saying?

Marca, the newspaper with closest links to the club, reports that Florentino Perez, the Real Madrid president, will not stand in Ronaldo's way if he wants to leave - somewhat contradicting reports that Madrid will demand 350m euros.

The same paper also says manager Zinedine Zidane and captain Sergio Ramos have both spoken to the forward and pleaded with him to stay.

El Pais reports that Mendes is currently seeking a new destination for his client, while Madrid are hopeful the player will have a change of heart in time.

Ronaldo's potential move away could stall Alvaro Morata's proposed move to Manchester United, according to AS.

Do people actually think he will go?

A Bola - the paper that first reported Ronaldo's discontent - says the decision he has made to leave Madrid is "irreversible".

The Sunday Mirror claims Ronaldo would be willing to stay in Spain if Madrid pay off his £13m fine if he is found guilty of tax fraud.

A poll of more than 45,000 fans on the Marca website found that only 40 per cent believe Ronaldo will leave the Santiago Bernabeu this summer.

What is his most likely destination?

If Ronaldo is to leave then his most likely destinations are Qatari-backed PSG or a return to Manchester United.

The French club are big admirers and tried to poach him last summer - to no avail.

However, it is United who are in poll position according to former Madrid president Ramon Calderon who brought Ronaldo to Real in 2009.

Calderon suggested that the player’s "love" for the "club, the fans, the city" means United is his likeliest destination.

You can read a full run down of his suitors here.