THE first public attempt to drop anchor on the canal project will be mounted this week.
The Labour group will present a motion at full council to call for a halt on the £52m project, championed by the conservatives.
Labour say that the Adver's recent survey, which revealed that two thirds of Swindonians are opposed to the canal, raised a number of questions about the plans.
Supporters of the project have hit back, accusing Labour of getting their sums wrong and lacking ideas of their own.
Coun Steve Allsopp (Lab, Parks), will present the motion - seconded by Coun Des Moffatt - at Thursday's council meeting.
He said: "I have had reservations about the canal project since we started running with it as an idea.
"There are a number of issues about which there are questions.
"The impact on the town centre, whether it will achieve its objectives, if we can deliver it within the cost envelope and whether it is the best use of money that will be spent on it.
"The Adver's survey has brought this to a head.
"More people with reservations about the scheme are surfacing all the time.
"Unless we test the council's water on this we are in danger of going forward with something people don't want.
"I have seen canals work in some places and I can understand the attractiveness of the concept.
"There's some sense of the canal as an exciting concept. I don't doubt that. Sometimes you let that run away with you. That is what has happened here."
Roy Cartwright, chairman of the Wilts and Berks Canal Trust, said that he was not surprised to hear about the motion, but was disappointed with Labour.
He said that a Labour leaflet pushed through his door by a candidate standing for election to Swindon council had made a number of claims about the costings for the canal which the trust disputes.
He said that the Labour candidate had either not read the canal feasibility study prepared by engineering company Halcrow or had misunderstood its findings.
Coun Phil Young (Con, Covingham and Nythe), cabinet member for economic development, regeneration and development, said that he understood people's concerns about the project but accused Labour of not having any ideas of their own.
He said: "It's understandable why they have put the motion forward. Labour have no aspiration, ambition or drive for the town centre.
"For that you need to think creatively and to have ambitions - the canal is a part of that.
"We accept that there are challenges that we have to address.
"What we are trying to understand is if this is an idea that will work for the town centre.
"We understand that there are questions which need to be answered and they will be."