Sánchez’s wife, Begoña Gómez, 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”.

Judge Juan Carlos Peinado, who is heading the inquiry, is scheduled to hear Sánchez as a “witness” at the Socialist premier’s official residence on July 30th.

But the public prosecutor’s office on Tuesday criticised the “haste” with which the judge summoned Sánchez and demanded that the hearing be called off.

It is said it “not useful” to ask Sánchez to testify, especially since he is not obligated to respond to the judge as Spanish law allows citizens to remain silent when an investigation concerns their spouse.

The prosecutor’s office — which has unsuccessfully requested the investigation be closed — also criticised the judge for carrying out his probe on a “manifestly disproportionate” manner and without a clearly defined purpose.

When the probe was opened in April, Sánchez shocked Spain by saying he was considering resigning over what he denounced as a campaign of political harassment by the right.

He took five days to reflect but ultimately decided to stay on.

Gómez, who has worked in fundraising for years, notably for foundations and NGOs, is alleged to have used her husband’s position as leverage within her professional circles, notably with businessman Juan Carlos Barrabés who was seeking public funding.

Barrabés – who teaches part of a master’s course at Madrid’s Complutense University that is run by Gómez – acknowledged meeting her five or six times at Moncloa, the premier’s official residence, while testifying.

Sánchez was also present at two of those meetings, he said.

Barrabés – who got two letters of recommendation from Gómez before pitching for a public tender worth several million euros – said they only talked about matters of innovation, judicial sources said.

Gómez on Friday invoked her right to remain silent under questioning by a judge.