Tomorrow, the ruling council of the owner, the Zoological Society of London, will decide whether to back the six-member board and terminate Dr Gipps's two-year contract.
The board asked Dr Gipps to resign last week. It is understood that members lost confidence in him because of his handling of annual pay negotiations with staff. According to one report, he offered more than the 1 per cent rise the board had agreed to.
He was appointed as director in February, after holding the position of acting director for several months. The previous incumbent, David Jones, was demoted and has since left.
Dr Gipps's appointment came after two years of strife and financial crises. Twice imminent closure was announced. News of his threatened departure caused dismay among staff, and some council members.
Dr Gipps said it was 'not in the interests of the zoo' for him to comment on the disagreement, but stressed that his integrity was not in question. He added: 'I am unswervingly committed to the zoo and its staff and to continuing in my position as director. I hope for a positive outcome.'