MADRID: Spain's King Juan Carlos has been plagued by health problems and unprecedented family scandals that have undercut public confidence in the monarchy during a bruising recession, but analysts say he is unlikely to abdicate anytime soon.

The 75-year-old monarch is credited with steering Spain to democracy following the death of dictator Francisco Franco in 1975 but his standing has suffered due to an elephant-hunting trip he took in Africa last year at a time of record unemployment in Spain and a corruption probe implicating his son-in-law.

Support for having a monarchy in Spain has fallen to a historic low of 54 percent, according to a poll published in daily newspaper El Mundo in January, with backing for the throne weakest among younger people.

Another poll published on March 8 showed 56.9 percent of Spaniards felt the king should abdicate in favour of his 45-year-old son Prince Felipe, once Juan Carlos recovers from surgery he had earlier this month for herniated discs in his lower spine, his seventh operation in three years.

But analysts say the king has a strong sense of duty and is unlikely to abdicate at a time when Spain is facing its worst economic downturn in decades, several political corruption scandals and a resurgent separatist movement in the northeastern region of Catalonia.

"The king's only intention at the moment is to recover as soon as possible and continue to work with all his strength to show that he is a capable man who continues to fulfil his role as king of Spain," said Abel Hernandez, who has published several books about Juan Carlos.

"If he were to abdicate, he would do it in good times, not at a moment of crisis when he is needed most," he added.

The monarchy has been rocked by an investigation into allegations that Inaki Urdangarin, who is married to the king's youngest daughter, Princess Cristina, syphoned off millions of euros paid by regional governments to a non-profit organisation he chaired from 2004 to 2006.

Urdangarin has not been charged with any crime and maintains his innocence but the high-profile case has cast a shadow over the entire royal family, especially after the longtime private secretary to the king's two daughters was summoned for questioning last month.

Despite the hit to his standing caused by his son-in-law's legal problems, the king is still an effective advocate for Spanish interests abroad and an active liaison between political leaders at home, according to analysts.

"He is the Spaniard and European with the best book of contacts in the world and we would be foolish and would be hurting ourselves if we did not value this," said Fermin J. Urbiola, a journalist who has written several books about the king.

King Juan Carlos used his friendship with his Saudi counterpart to help a Spanish consortium win a multi-billion-dollar contract in 2011 to build a high-speed railway in Saudi Arabia and he often helps smooth out diplomatic spats between Spain and other countries.

The king "is very good in his role as a mediator", added Hernandez.

"He is constantly on the phone to carry out his role as head of state. This is not a king who is on holiday."

The king -- who helped fend off an attempted military coup in 1981 -- had a benign tumour removed from a lung in May 2010.

He appeared hobbling around on crutches last year after having hip replacement surgery.

But during a televised interview in January to mark his 75th birthday, the king said he was in "good form" and had "energy and hope" to carry on his rule.

Unlike in the Netherlands where 75-year-old Queen Beatrix announced in January that she would end her reign later this year and pass the crown to her eldest son, in Spain there is no tradition of abdications due to old age, said Yolanda Gomez, a constitutional law professor at Spain's UNED university.

"Politically this is absolutely not the time for the abdication of the head of state. An abdication should take place during the best possible political situation, not at a time of political tension," she added.

King Juan Carlos should wait until the legal proceedings against his son-in-law are over before abdicating, said Eduardo Virgala, a constitutional law professor at the Basque Country University.

"That would allow the king to leave a clean situation to his heir," he said.

Crown Prince Felipe, who studied in the United States and Canada and is married to former television news anchor Letizia Ortiz, has seen his standing increase in recent years as he has taken on more official engagements.

A large majority of Spaniards, 85.9 percent, feel he is "well prepared" or "very well prepared" to assume the throne, according to the TNS Demoscopia poll released earlier this month.

"The king's image has suffered some deterioration while Felipe's standing has consolidated as that of someone who is well prepared, who can take the reins of state at any time," said constitutional law expert Antonio Torres del Moral of UNED university.