By Amanda Cooper

MADRID (Reuters) - Spain's governing People's Party (PP) will go on trial for destroying two laptops used by a former treasurer who is already being tried for his involvement in an alleged party slush fund, a Madrid court said on Tuesday.

The PP would be treated as an individual and brought to trial with the party's new treasurer, Carmen Navarro, on charges of perverting the course of justice and destroying the two laptops, the court ruled.

The center-right PP lost its majority in an inconclusive election last December but has since been in charge of the caretaker government as parties struggle to form a coalition. A June election did little to resolve the impasse.

The court is at present trying six PP members including the former party treasurer, Luis Barcenas, on charges of organized crime, falsifying accounts, influence-peddling and tax crimes.

Barcenas has said the two laptops mentioned in the new court ruling on Tuesday belonged to him when he was party treasurer.

The PP said in a statement it would appeal the judge's decision and that the accusations were false and politically motivated. It said it stood firmly behind current members of the party under investigation.

Acting Prime Minister Mariano Rajoy's PP has been trying to clean up its image after a spate of graft scandals, some of which have involved the party's leadership in Madrid.

Spaniards' disgust with corruption scandals that have tainted both the PP and its arch-rivals, the Socialist Party, led to the rise of new parties that split the vote in December as well as in June.

However, despite a fresh spate of scandals since the Dec. 20 ballot, Rajoy's PP picked up an extra 13 seats in the election re-run last month. Rajoy is in discussions with other parties to reach an agreement to form a government.

PP employees wiped and disposed of hard disks from the laptops after Barcenas was barred from entering the party's central Madrid headquarters in early 2013, according to the court document.

The PP will be indicted "for not having created an adequate organizational and management framework to prevent this crime from taking place ... there is no internal security protocol," the court said.

The PP itself and treasurer Navarro will appear along with the party's head of legal services Alberto Duran and Jose Manuel Moreno, a computer engineer, the court said.

(Additional reporting by Sarah White editing by Mark Heinrich)