The ad hoc meeting with Peter Chermeyeff was the first of a series at which New Zoo Developments, the consortium led by David Laing, of the construction family, hopes to persuade sceptics that its ambitious plan is the best hope for keeping the zoo open. The plan includes a vast walk-through aquarium and Chinese-style rainforest terraces.
Meanwhile, taxi drivers and schoolchildren are to be the first targets in the other main campaign to save London Zoo. David Bellamy, the naturalist and zoo council member, yesterday launched the campaign by the London Zoo Survival Group. This represents staff from the Zoological Society of London - the zoo's parent body. The group wants the zoo to concentrate on its conservation work and use this to attract more visitors.
The survival group has a tight budget and hopes to persuade the London Taxi Drivers' Association to give it space for a sticker in every cab to advertise the zoo.
The Conservation Foundation, Professor Bellamy's campaigning organisation, also plans to include leaflets from the group in a mailshot to London schools.
Some fellows of the Zoological Society think that zoos designed by Mr Chermeyeff are not as good for the animals as they appear. The emphasis at his zoos in the United States is on providing a natural-looking setting.
But sceptics say mortality rates are high. They claim sharp metal trees at the zoos are easy to clean but have been responsible for several animals' deaths. They also claim that animals not suited to living together are often kept in the same enclosure.
Real greenery is often protected from the animals by sheets of glass or 'hot wires', the critics say, leaving frustrated animals without even the old-fashioned cardboard box or rubber tyre to play with. These would spoil the 'natural' effect for visitors.
The consortium presenting Mr Chermeyeff's design is backed by Samuel Montagu, the merchant bank, which is raising the pounds 61m that the plan requires.
Last week, representatives from the consortium met Sir John Chapple, the president of the Zoological Society. Next week it will explain its ideas to the Zoo Council, which last month voted for closure.
The Survival Group's next target is the Government. It will seek meetings with David Mellor, Secretary of State for National Heritage, and with John Major, to discuss its plans for a conservation-based zoo.