* Lawmakers from Berlusconi's party protest outside court
* Former PM says eye problems prevent attendance at trial
* Three doctors, including top eye specialist, make checks
* Berlusconi charged with paying for sex with minor
* "Ruby" trial was meant to start on Monday
By Sara Rossi
MILAN, March 11 (Reuters) - Dozens of parliamentarians from Silvio Berlusconi's centre-right party demonstrated on Monday outside the Milan court hearing the former Italian prime minister's trial on charges of paying for sex with a minor.
The demonstration came after the judges ordered checks to be made on Berlusconi to verify his claim that an eye problem meant he was unable to attend a hearing on Monday. Following a visit by three doctors, including a senior eye specialist, the hearing was postponed until Wednesday.
The checks add to an increasingly bitter legal and political battle around the 76-year-old media billionaire as parties struggle to deal with the aftermath of February's election which left none of them able to form a government.
"We consider this scandalous and not worthy of the normal functioning of a justice system in a civilised country. It is extremely serious," Angelino Alfano, secretary of Berlusconi's People of Freedom party.
Berlusconi, who faces a series of court hearings in separate trials this month, has been in the San Raffaele hospital in Milan since Friday because of an eye problem that he says has forced him to cancel a number of public appointments.
However prosecutors argued that his stay in hospital was only a delaying tactic and on Saturday judges rejected his argument that he was unable to attend a separate trial for tax fraud because of the same eye problem.
The head of Italy's National Magistrates Association, Rodolfo Sabelli rejected the accusation by Berlusconi's party that judges were acting out of political motivation.
"The magistracy is not a political organization, what magistrates do is not political and the objectives of magistrates are not political," he told SkyTG24 television.
Monday's hearing had been expected to be one of the final dates in the case, in which Berlusconi is charged with paying for sex with former nightclub dancer Karima El Mahroug, better known under her stage name "Ruby", when she was below the minimum age of 18. A final ruling is expected on March 18.
The "Ruby" case was the most spectacular of a series of financial and sexual scandals which tarnished the image of Berlusconi's government in the months before it fell at the height of the euro zone debt crisis in late 2011.
He denies any wrongdoing and says he has been subject to politically motivated "judicial persecution" by what he says are left-wing judges who want to end his political career.
Earlier, the court rejected a request by Berlusconi's two main lawyers for the trial to be delayed because they had to attend a meeting of his People of Freedom party, which they both represent in parliament.
Berlusconi's centre-right alliance holds the second-biggest bloc in parliament but appears to be shut out of government by the hostility of both the centre-left Democratic Party and the anti-establishment 5-Star Movement of former comic Beppe Grillo.
In addition to the "Ruby" trial, Berlusconi is also appealing against a four-year jail term for tax fraud in connection with the purchase of broadcasting rights by his television network Mediaset.
On Monday, prosecutors in Naples requested a fast-track judgement in a separate case in which Berlusconi is suspected of paying former Senator Sergio De Gregorio to change sides in 2006 in a move which helped bring down the centre-left government of former Prime Minister Romano Prodi.