DETROIT (AP) – Prosecutors accusing Detroit Mayor Kwame Kilpatrick of lying on the witness stand to cover up an extramarital affair with a top aide said Wednesday that a plea deal is expected soon, a surprise development that appeared likely to cost him his job.

The office of Wayne County prosecutor Kym Worthy said Wednesday that an agreement is expected soon, first saying it would come that afternoon and later saying it would be Thursday morning.

The Detroit city charter automatically expels any mayor guilty of a felony. Kilpatrick is charged with eight felonies in the perjury case and would have to get them all reduced to misdemeanors – or beat the charges in court – in order to keep his job.

A member of the mayor’s legal team cautioned that talks continued.

“The plea deal has not been consummated. They’re still working out the finer points,” lawyer James Thomas said after spending the day defending Kilpatrick at a separate hearing led by Gov. Jennifer Granholm.

The City Council has asked Granholm to use her constitutional authority to expel Kilpatrick for misconduct, saying it was misled when it approved an $8.4 million settlement last year with fired police officers.

Council members say they didn’t know the deal carried secret provisions to keep a lid on steamy text messages between Kilpatrick and Christine Beatty, who was his chief of staff, on city-issued pagers.

Kilpatrick spokesman Chris Garrett told The Associated Press that a statement from the mayor’s office was not expected Wednesday night and that negotiations with prosecutors continue.