MADRID   -   Spanish Prime Minister Pedro Sanchez agreed Wednesday to testify in a preliminary corruption probe into his wife Begona Gomez’s business dealings but said he would do so in writing.

Gomez is being investigated for alleged influence peddling and corruption following a complaint filed by an anti-graft NGO with links to the far-right called “Manos Limpias” -- Spanish for “Clean Hands”.

Sanchez has denied any wrongdoing by his wife and has repeatedly dismissed the allegations as part of a right-wing smear campaign against his leftist government. But the case has deepened a perception of a fragile leader and stoked acrimony in Spanish politics.

He has struggled to pass legislation since he returned to power last year after an inconclusive election as head of a fragile coalition that relies on a patchwork of smaller parties to approve bills.

Spanish lawmakers on Tuesday rejected the government’s fiscal targets, a mandatory step before the government can table a budget. Judge Juan Carlos Peinado, who is heading the inquiry, said Monday he would question Sanchez on July 30 at the premier’s official residence as part of his probe into the influence peddling allegations against Gomez. But in a court filing sent to the judge on Wednesday, Sanchez said he would “cooperate” with the investigation but “because of my position as prime minister, my statement will have to be made in writing”, as allowed under Spanish law. “As prime minister, it is my duty to respect the law and preserve the proper functioning of the institution I represent,” Sanchez said.