A dental worker who lost her job while on maternity leave is suing the Prison Service for unfair dismissal.

Caroline Birks, of Ravencroft, Bicester, claimed managers at Grendon and Springhill Prisons in Buckinghamshire deliberately failed to tell the NHS Primary Care Trust, who have taken over running of healthcare at the prisons, that she was an employee and due to return to work.

As a result, she was informed there was no job for her when she planned to go back to work after giving birth in the summer of 2006.

Representing herself at an employment tribunal hearing in Reading, she said: "I was due to return from maternity leave on November 6, 2006. I sent numerous letters but did not have any reply. When I spoke to Trevor Ballinger, the healthcare manager at the prison, about two weeks before I was due to return to work, he said I was not needed because the new provider was bringing in a new nurse. He said there was no job for me because the Primary Care Trust had contracted a nurse to provide dentistry."

At a preliminary hearing, the tribunal heard how there was a dispute over who employed the dental nurse - the Prison Service or the Primary Care Trust.

Mrs Birks, who now is six months' pregnant, is suing for sex discrimination, breach of contract and unfair dismissal. She was told the hearing would be delayed until January 22 next year in order for her to give birth.

Prison Service solicitor Angus Edwards said there was also a chance the claim had been put in too late for it to be legal, because of discrepancies over when the employment was actually terminated.