Sixty-two percent of Spaniards want their country's scandal-hit King Juan Carlos to abdicate and fewer than half support the monarchy in general, a poll published on Sunday showed.
A majority however support the king's son and heir Felipe and believe he could restore the family's prestige, according to the study by pollster Sigma Dos for El Mundo newspaper.
Juan Carlos, who turned 76 on Sunday, has seen his popularity plunge over the past three years, largely due to a corruption scandal centred on his son-in-law and a luxury elephant-hunting trip the king made to Africa in 2012.
He has also suffered from ailing health, which together with the scandals have raised speculation about the future of his reign.
The number of people with a high or very high opinion of the king fell nine points over 2013 to 41 percent, according to the new poll, carried out in late December.
The number of people wanting him to abdicate in favour of Felipe surged by 17 percent to 62 percent.
Support for the monarchy as an institution fell below half, to 49.9 percent, according to the poll.
Juan Carlos is widely respected for his role in Spain's transition to democracy after the death of dictator General Francisco Franco in 1975, but the king's image has been tarnished in recent years.
A judge since 2011 has been investigating alleged embezzlement by the husband of his youngest daughter Cristina, former Olympic handball player Inaki Urdangarin.
The judge in that case is also due to rule on whether to summon Cristina herself as a formal suspect for alleged tax evasion and money laundering.
The king also lost sympathy last year for going on an expensive elephant-hunting trip in Botswana, while Spaniards struggled through a recession.
The king has appeared in public on crutches in recent months and in November surgeons replaced his left hip, his ninth operation since May 2010.
He has had surgery on a benign lump in his lung, his right knee, an Achilles tendon, a slipped disc, two operations on his right hip and three on his left.
Ahead of his last operation, the palace firmly denied the king was considering abdicating.