Supporters of Spain's prime minister rally in Madrid to urge him not to quit

MADRID (Reuters) - On the eve of Spanish Prime Minister Pedro Sanchez's dramatic announcement about his future, thousands of Socialist Party supporters rallied in Madrid on Sunday to ask him to stay on after he stunned the country this week by saying he might quit.

Sanchez said on Wednesday he would step back "for a few days" to decide whether he wants to continue leading the government after a court launched a corruption investigation into his wife's private dealings. He said this was part of a sustained campaign of slander against him and his family by political opponents.

Sanchez denies the allegations made against his wife, Begona Gomez, and said he will announce his decision on his future on Monday.

Carrying posters reading "Don't give in" and "For the love of democracy", about 5,000 of Sanchez's supporters marched to the Spanish parliament to urge the prime minister to stay, according to an estimate by the Spanish government.

"I have come to demonstrate because of all the media pressure that is being put on the government and because of the fraudulent use of the judiciary in a case involving the president's wife where there is still not enough basis to start a trial," Marcos Riera, 34, a university lecturer, told Reuters.

Opposition parties said the reputation of Sanchez, who came to power in 2018, was already in tatters.

"I don't know what he's going to say tomorrow, but whatever he says, he will be forever marked by the decadence he has brought to our country," Alberto Nuñez Feijoo, the leader of the opposition conservative People's Party, said on Sunday at a meeting in Lleida, in Catalonia.

Madrid's prosecuting authority said on Thursday it was appealing the decision by a city court to look into the private complaint laid by an activist group against Gomez over alleged influence peddling and business corruption.

(Reporting by Graham Keeley; Editing by Ros Russell)