The judicial noose tightened Tuesday around Spain's ruling Popular Party, which is engulfed in a series of graft scandals, making it harder for it to retain power after an inconclusive general election.
Rita Barbera, a Popular Party (PP) senator who governed Valencia, Spain's third-largest city, for more than two decades, agreed to be questioned by a judge investigating alleged money laundering by the conservative party.
Barbera made the announcement after Spanish media on Tuesday published excerpts of a recording of a telephone conversation by her former advisor, Maria Jose Alcon, explaining how Alcon laundered 1,000 euros ($1,100) in party money.
"In this country the only thing that works is corruption," Alcon can be heard telling her son in the police recording made a year ago which dominated headlines on Tuesday.
The recording was made as part of a probe into a suspected kickback scheme that operated in the eastern region of Valencia, a PP fiefdom until 2015 when voters turned to the left in regional elections.
The authorities are looking into allegations that companies, mostly from the building sector, paid commissions in exchange for public works contracts which helped finance the PP in the region. In the recording Alcon tells her son the party was full of "black" money and suggests one of Barbera's secretaries requested the operation to launder it.
The investigating judge in the case on Monday placed the PP under official investigation for money laundering and asked to question Barbera.
The former Valencia mayor told a news conference on Tuesday the allegations against her were "unfounded" and "completely false" and she had not committed any crime.