Susan Marshall, who was born Simon Stone and had a successful legal career as a male naval officer, launched a sex-discrimination complaint against Dame Barbara and the Crown Prosecution Service after an offer of a job in the general casework division was withdrawn.
Ms Marshall, now 50, had presented herself for an interview in March 1993 in her former male role, and the following week was offered a more senior post by telephone. But she had been receiving medical treatment for gender identity disorder - transsexualism - since 1988 and wanted to take up the job as a woman.
Several years earlier she had begun living as a woman when on leave from the Royal Navy, and eventually felt compelled to take voluntary early retirement, leaving with the rank of commander. She was then appointed home bursar at Exeter College, Oxford. By late 1992 she had decided to change over to living full-time as a woman.
Ms Marshall wrote a personal letter to Dame Barbara setting out her circumstances, and stating that she wished to work for the CPS as a woman. Dr Russell Reid, Ms Marshall's consultant psychiatrist, also wrote to the DPP, saying she had a "very convincing feminine appearance and has no difficulty being fully accepted in the female role".
The DPP said in her reply that whilst she sympathised with Ms Marshall's dilemma she considered she had "underestimated the extent to which lawyers in the Crown Prosecution Service can be exposed to searching public and media attention".
Ms Marshall proceeded to live permanently as a woman and reluctantly let the matter of the CPS job drop, until a landmark ruling by the European Court of Justice last year established that transsexuals employed in the public sector were protected by the Equal Treatment Directive.
Ms Marshall filed an industrial tribunal complaint and got the go-ahead to pursue her case even though it had been launched outside the three- month statutory time limit. The DPP and the CPS are currently contesting that decision.
Last month, the Employment Appeal Tribunal went further than the European Court, ruling that anyone who has a gender change is protected from discrimination by the 1975 Sex Discrimination Act. The Government is now considering how to reflect the ruling in legislation.
A spokesman for the CPS said: "We are fully committed to a policy of equal opportunity in employment practice. We shall contest this industrial tribunal application on ... the circumstances of this particular case."