The Court of Cassation rejected an appeal by the former head of state against the legality of intercepts of two mobile phones rented for him under an alias after he left office.
That opens the way for him to stand trial for allegedly trying to bribe a justice official to leak information to him in another probe. He has denied any wrongdoing.
Yesterday’s ruling added to a cloud of legal woes hanging over the leader of the centre-right Republicans party, making it harder for him to stand in November for the conservative nomination for next year’s presidential election.
Mr Sarkozy was president from 2007 to 2012 but was defeated by Socialist François Hollande when he ran for re-election.
He has since faced a series of investigations into alleged corruption, fraud, favouritism and campaign funding irregularities.
He was put under investigation last month in a separate probe into breaches of the legal spending limits on his re-election campaign.
Mr Sarkozy has not yet said whether he will enter the contest.