The mayor of the Italian city of Venice, Giorgio Orsoni, has resigned amid a wider investigation into alleged corruption over new flood barriers.
He and 34 other officials were arrested last week on suspicion of embezzling around 20m euros ($27m, £16m) in public funds earmarked for flood defences.
Mr Orsoni stepped down a day after being released from house arrest under a plea bargain.
He agreed to a four-month sentence but is unlikely to go to prison.
The sentence still requires court approval.
Mr Orsoni had returned to his post on Thursday after a temporary suspension but it appears he lost the support of his political allies, the ruling centre-left Democratic Party, correspondents say.
He had told a prosecutor he was innocent in the case. Speaking to reporters after his release from house arrest, he said he had always run Venice "in the best way possible".
"I made a lot of enemies... and this is the price I am paying," he added.
The bribery allegations centre around the public tender process for the Moses project, as the works are known in English, after their Italian acronym (Mose).
Seventy-eight mobile barriers will be used to shut off Venice lagoon in the event of rising sea levels and storms.
Construction began 11 years ago but has been hampered by delays in funding due to the economic crisis.
The city, one of the world's great tourist destinations, is continuing to sink and is hit by flooding on a yearly basis.