MADRID—A top Spanish court sentenced the former treasurer of the country’s ruling party to jail for his role in a kickback scheme and fined the party, a milestone in a long-running corruption saga that deals a blow to Prime Minister Mariano Rajoy’s already unsteady hold on power.
Spain’s National Court said in its ruling that Mr. Rajoy’s Popular Party financially benefited from the scheme and ordered it to pay €246,000 ($288,000) in fines.
...