(ANSA) - Sanremo, February 18 - The 64th edition of Italy's storied Sanremo music festival was set to kick off Tuesday night with pundits predicting success despite a flap over gay rights, the looming presence of foul-mouthed comedian-turned politician Beppe Grillo and a teary pre-fest press conference by the wives of two marines trapped in a judicial quagmire in India. The prime-time television extravaganza broadcast live by state broadcaster RAI 1 from the Ariston Theatre in the Ligurian coastal town will see performances by 14 big names in Italian popular music and eight newcomers: Bianca, Vadim, Veronica De Simone, Filippo Graziani, Rocco Hunt, The Niro, Zibba and Diodato.

Big names to look out for over the five-day event include Arisa, who won first place in the newcomers' section in the 2009 edition of the festival with her entry Sincerità, Giusy Ferreri, Raphael Gualazzi, Cristiano de André and Antonella Ruggiero.

In addition, Friday evening will be dedicated to songs that have made Italian musical history, performed by renowned singers and/or personalities from the world of show business. As always, the music programme will be punctuated with appearances by special guests from the world of music and beyond.

This year the line-up includes French actress and model Letitia Casta, Yusuf Islam, the British singer-songwriter formerly known as Cat Stevens, Scottish singer-songwriter Paolo Nutini, Italian astronaut Luca Parmitano, Irish singer-songwriter Damien Rice, American-Canadian singer-singwriter Rufus Wainwright, Belgian hip hop artist Stromae and Luciano Ligabue. On Tuesday, the openly gay Wainwright defended his appearance after criticism by members of a Catholic youth organisation amid controversy surrounding a Wainwright song which they said was "blasphemous". "His song Gay Messiah ... is not meant to be 'blasphemous' as it is not a portrayal of Jesus or any religious figure in the canon of the Catholic Church but a metaphor for a world where gay people enjoy the same rights as heterosexual people which judging by the reactions in Italy is still very far away," said a spokesperson in a statement.

"It is sad that a lot of the members of the Catholic Church seem to trail far behind their leader Pope Francis in his respect and acceptance for women, gay people and other minorities," the statement said.

On Monday RAI 1 Director Giancarlo Leone said Wainwright's appearance was not intended to cause a scandal.

"The difference between commercial television and RAI is exactly in the fact that we have Rufus Wainwright and the others do not. "We have no intention of creating controversy using this singer, who was, among other things, defined by Elton John as the greatest songwriter in the world".

Wainwright was scheduled to perform two songs, John Lennon's 'Across the Universe' and his own 'Cigarettes and Chocolate Milk', but not the controversial 'Gay Messiah'.

Meanwhile organisers were bracing for the announced 'participation' of ex-comic Grillo, leader of the anti-establishment Five-Star Movement, who said he would be staging a protest both outside and inside the Ariston during the opening night.

Though it was unclear what the firebrand leader had in mind, organisers feared contestations along the lines of those that interrupted a performance by satirical comedian Maurizio Crozza in 2013, causing the artist to abandon the stage.

Crozza is scheduled to return to the Ariston stage this year for the final evening on Saturday. And the wives of two Italian servicemen facing terror charges in India for allegedly killing two Indian fishermen during an anti-piracy mission in 2012 used a pre-festival press conference to reiterate their trust in the institutions and raise public awareness of their partners' plight. "We have never lost faith in Italy's institutions," said Vania Ardito, whose husband Salvatore Girone is accused together with Massimiliano Latorre of killing fishermen Valentine (aka Gelastine) and Ajesh Binki after allegedly mistaking them for pirates and opening fire on their fishing trawler while guarding the privately owned Italian-flagged oil-tanker MT Enrica Lexie off the coast of Kerala on February 15, 2012.

"This is the third government to take office but our trust remains," she continued in reference to the team currently being put together by Premier-designate Matteo Renzi following the resignation of Democratic Party (PD) colleague Enrico Letta last week.

A technocrat government led by Mario Monti was in office when the incident happened. "They are the ones who must bring Salvatore and Massimiliano home".

The fest is being hosted for the second year running by television presenters Fabio Fazio and comedian Luciana Littizzetto.

Last year they faced question marks that their left-leaning politics might stray onto the stage but even their sternest critics were disarmed by madcap Littizzetto's barnstorming comedy routines and Fazio's polished performance as MC.