By Sarah Morris and Iciar Reinlein
MADRID (Reuters) - Tens of thousands of wildlife activists have demanded that Spain's King Juan Carlos step down as honorary president of the World Wildlife Fund Spain after it emerged he had gone on an elephant hunt in Africa.
The king's hunting trip to Botswana last week was revealed when he was flown back to Madrid for medical attention after slipping on a step and breaking his hip.
Animal rights supporters have called a rally for Tuesday outside the hospital where he is recovering.
The WWF Spain has also written to the royal household to request a meeting with officials to convey the outrage of thousands of activists over the trip, although it stopped short of telling the king to resign from his post.
"We are deeply sensitive to the concerns expressed and the serious damage this outcry is causing to the credibility of WWF and the hard work that has developed over 50 years for the protection of elephants and other species," WWF Spain Secretary General Juan Carlos del Olmo wrote in a letter, seen by Reuters.
Tens of thousands of people have criticized the king on social media and demanded he is removed as honorary president, it said.
As well as environmentalists, the 74-year-old king was attacked by media and politicians for his extravagant foreign trip at a time of high unemployment and painful austerity measures.
Some commentators called for him to apologize or even to abdicate in favor of his son Felipe.
"The moment has come for the royal family, in this case the head of state, to consider whether it wants the obligations and servitudes of public responsibilities or a situation that would allow him to enjoy a different life," said Tomas Gomez, leader of Madrid's Socialists.
Gregorio Peces-Barba, a Socialist who helped draft Spain's post-dictatorship 1978 Constitution, criticized the king's behavior and said he went too far in his freedom.
Juan Carlos, who oversaw the country's tense transition to democracy, won respect from many Spaniards in 1981 when he publicly condemned an attempted military coup.
He has remained very popular but his family has recently come under fire after the king's son-in-law, Inaki Urdangarin, was charged in a fraud and embezzlement case.
The royal family is also facing questions about why his 13-year-old grandson of the king was using a firearm while under-age. Felipe Juan Froilan accidentally shot himself in the foot last Monday while doing target practice.
(Editing by Julien Toyer and Angus MacSwan)