Lindsay Lohan's lawyer has quit just a day before she is due to go to jail.

Robert Shapiro was expected to represent the 'Mean Girls' star today (20.07.10) in court ahead of her scheduled prison term, but has now left the job for unknown reasons.

The lawyer - who formerly represented O.J. Simpson - revealed last week he would only represent the 24-year-old actress if she agreed to certain conditions.

He said in an official statement: "I have agreed to represent Ms. Lohan on the condition she complies with all of the terms of her probation, including a requirement of jail time that was imposed by Judge Marsha Revel."

Lindsay then entered sober living facility Pickford Lofts, which was founded by Shapiro, which she has now moved out of ahead of her jail stay.

Shapiro told Judge Marsha Revel in her chambers he was no longer representing her yesterday (19.07.10).

Meanwhile, Lindsay has shown her humorous side ahead of her prison sentence, revealing her unfamiliarity with the term "bookings".

Writing on twitter, she said: "the only "bookings" that i'm familiar with are Disney Films, never thought that i'd be "booking" into Jail... eeeks (sic)"

Lindsay has to surrender to a Beverley Hills court at 8.30am today (Pacific Daylight Time).