Spain's main opposition conservative People's Party (PP) was Thursday fighting off allegations of high-level corruption within its ranks after one of its key regional leaders resigned, according to dpa. Leading PP politicians defended the innocence of Francisco Camps, who stepped down as prime minister of the eastern Valencia region on Wednesday. Meanwhile, Prime Minister Jose Luis Rodriguez Zapatero's Socialists and other leftist politicians stressed the seriousness of the charges against Camps. Camps is facing trial on charges of having accepted gifts, including 25 suits worth a total of 14,000 euros (19,600 dollars), from companies which were awarded contracts allegedly in exchange for bribes. The suits are allegedly only the tip of the iceberg of long-running corrupt practices in the region. Camps is one of around 20 PP politicians implicated in the so-called Guertel affair, in which businessman Francisco Correa faces charges of having run a corruption network in several regions. The affair, which is regarded as one of Spain's biggest ever political corruption scandals, has been running for more than two years. It earlier led to the resignation of a PP treasurer, several mayors and a European legislator. Camps maintained his innocence, saying he was making a sacrifice to help his party, on announcing his resignation in Valencia. The publication of details of his alleged involvement with the Guertel network would have damaged the PP in the March 2012 general elections. Current polls give the party a strong lead against the Socialists. PP leader Mariano Rajoy had refrained from openly asking Camps to resign, despite mounting pressure on him to do so. Government spokesman Jose Blanco accused the PP of downplaying the "serious" affair, but several PP politicians stressed their faith in Camps' innocence. His resignation gave an "example" to Spain's political class, Madrid regional Prime Minister Esperanza Aguirre said.