The meeting is not expected to decide on a winning bid, even though the official closure date is fast approaching. On Friday, a spokesman for Mr Laing's consortium was confident that the zoo would opt for his entrepreneurial plan, but said he was exasperated by its prevarication.
The zoo's council is waiting for the result of a postal ballot of the 2,000 fellows of its parent body, the Zoological Society of London, to be announced on 14 September. The management insisted on the ballot despite suffering a strong vote of no confidence at a fellows' special general meeting in July.
If the ballot also goes against the management, and soundings indicate it will, members will be under considerable pressure to step down at the council's next annual meeting on 30 September - the official closure date.
Seven vacancies on the council are to be filled at this meeting and the new council is expected to make a final decision on the bids in the first week of October.
The dissident fellows' Reform Group has yet to put its weight behind any single plan, but believes that a newly-formed council could keep the zoo open until next autumn, given the pounds 1m donation from the Emir of Kuwait, pounds 300,000 raised in last year's Save Our Zoo campaign, and increased attendances in recent weeks - an ironic benefit of publicity surrounding the crisis.
Colin Tudge, a founder member of the Reform Group, believes that within 12 months a new council could show that the zoo can pay its way on a day-to-day basis, and could demonstrate its own competence by sticking to a financially and philosophically sound plan. It could then approach the City for fresh funds.
Mr Laing's bid is fronted by a company called New Zoo Developments, with the promise of equity via Samuel Montagu, the merchant bank, and Daiwa, the Japanese securities house. It drew much criticism early on, as it involved spending large sums on new enclosures, including a cinema complex and an ambitious aquarium.
Opponents feared the plan would turn the zoo into a 'theme park', submerging its conservation role.
The proposal has now been re-formulated to take account of these views, and is deemed fairly sound by critics.
The staff plan draws on a broad base of ideas from within the zoo. The staff would form a charitable trust - the London Animal Survival Trust - to run the zoo, with a strong emphasis on its role as a centre for conservation and captive breeding. The trustees would come from among the staff, unions and the society. They would appoint a chief executive and a full-time, paid staff.
There is little to choose between the management's plan and the staff initiative. The former is expected to cost about pounds 10m- pounds 15m over the next 20 years. Jo Gipps, chief executive at the zoo, said several anonymous investors were ready to put up money.