Madrid, March 6 (RHC)-- A Spanish judge has ordered the trial of 40 individuals, including former mayors and businessmen affiliated to the ruling Popular Party (PP), on charges of involvement in a kickback scheme and alleged corruption crimes.

On Thursday, Spanish High Court Judge Pablo Ruz ordered three former PP treasurers -- Luis Barcenas, Alvaro Lapuerta and Angel Sanchis -- as well as former Health Minister Ana Mato to stand trial. Mato stepped down last November, saying at the time that she had no knowledge of the kickback scheme.

The judge also imposed court bonds worth a total of EUR 449 million (USD 500 million) on 36 of the 40 suspects. Those charged in the so-called Gurtel graft case are said to have taken bribes, including luxury gifts and hotel stays, in return for public contracts. They are also accused of influence-trafficking and embezzling public funds.

Barcenas faces the highest court bond of EUR 88 million (USD 97 million). He purportedly rerouted donations from builders and other business leaders into PP leaders' accounts.

Spain's ruling party is facing a tough challenge to garner public support ahead of general elections, which are slated for the end of the year as the emerging Podemos Party has considerably improved its ranking in the opinion polls over the past months. The far-left party has vowed to stage a massive fight against state corruption and revoke government policies aimed at reducing public spending and squeezing salaries and pensions.

Podemos' base of support was further boosted in January, when its ally in Greece, Syriza, won the general elections there.