They narrowly supported three motions that universally condemned the use of such contracts, meaning a further motion urging the National Executive Committee to lobby Parliament for an outright ban subsequently fell.
Code of practice
Moving the first successful motion Philip Williams (CMD Central London) callled for Prospect to work with other unions to develop a code of practice wherever such contracts are used, and to work for their replacement by suitable alternatives.
He said: "Few of us are unaware of the inequities of zero hours contracts... Their increasing use is all about giving the employer enormous power over the worker and reducing the worker's status to near slavery."
Many zero hours contracts were not real jobs at all, as they did not afford workers either a living wage or any dignity, he added.
However, Williams conceded that there are "limited circumstances" where no fixed hours may benefit a few workers; where they may want flexibility, or for specialised workers who could command very high fees for short periods of work.
In her first visit to conference, Janice McMillan (Air Traffic Systems Specialists) moved a successful motion calling on the NEC to offer guidance for branches on best practice with zero hours contracts and to press for proper government regulation.
Figures from the Office for National Statistics show 1.4m people now work on zero hours contracts, she said.
The effect of these pernicious contracts was "no security for the employee, and it is the vulnerable taking these contracts, such as the young, women under 25 and over 65. They are unable to budget and to support their families.
"Some of the workers are afraid to look anywhere else for work and frightened to turn down hours for fear of nothing at all... causing stress, uncertainty and a shrinking wage packet."
She added that zero hours contracts did benefit some people, such as students, who make up one quarter of all workers on these contracts.
Robert Walker (Rosyth Royal Dockyard) also won support, calling on the NEC to conduct more research and data on the prevalence of these contracts and to work with employers and other trade unions to end their exploitative use.
He said the contracts "do have some advantages for people who want occasional earnings and are in the enviable position of being entirely flexible about when they work. If people are studying or need childcare, then it's easier to juggle things around.
"If used appropriately, they can provide flexibility for both the employer and employees. However, they are not for the majority of the working population. Workers subject to these contracts are also subject to exploitation."
Moving the unsuccessful call for a lobby of parliament to outlaw these contracts Chris Hardy (Scottish and Southern Energy) told conference about his young daughter. She was on a zero hours contract in the fast food industry but didn't have any work for five weeks because the shop was being refitted. He called the contracts "socially destructive" and argued that the other motions didn't go far enough.
Gerard Kerins (Environment, Food and Rural Affairs) said his branch was fundamentally opposed to the contracts. "The idea of codes of practice may be a distraction from the fundamental goal of abolishing these contracts," he said. "A couple of the speakers said there may be incidences where flexibility may be useful. Our understanding is that the flexibility is always with the employer, so we don't accept that."
Suzanne Burge (London & South East Regional) said her branch opposed a blanket ban, while agreeing with all that had been said about the inequities of zero hours contracts. "There are industries which exploit them hideously and mistreat their workers dreadfully.
"But there are people for whom zero hours contracts work. Professionals who have specialist skills, such as architects, find them useful with small firms who may want to call on their skills. I'm told it is particularly helpful if you are working towards retirement... You can pick up jobs this way."
Delegates have been blogging about their conference experiences.