Ms Shoesmith said she was shocked how political the case became
The former head of children's services at Haringey Council has lodged a claim against the north London authority.
Sharon Shoesmith was sacked without compensation in December following a critical report into the authority's handling of the Baby P case.
The 17-month-old had more than 50 injuries by the time he died in 2007.
Ms Shoesmith lodged the claim against the authority with the Watford employment tribunal on Friday, a Tribunals Service spokeswoman said.
A spokesman for Haringey Council said: "We will be contesting this vigorously."
Children's Secretary Ed Balls sent inspectors into the local authority after the trial of those responsible for Baby P's death.
The inspectors identified "serious concerns" about Haringey's child protection services, which they described as "inadequate".
Ms Shoesmith lost an internal appeal against her dismissal in January.
Baby P had been on the child protection register and was seen by professionals 60 times.