About 350 offenders would visit the site every week
The justice minister has agreed to consider alternative sites for a new probation centre in Oxford, according to the Oxford West and Abingdon MP.
Dr Evan Harris arranged for local residents and councillors to meet Justice Minister David Hanson MP in Westminster.
Campaigners have been fighting plans for a "super probation centre" in Mill Street, West Oxford.
The Probation Service wants to merge four of its branches on to one site.
The service said it was facing financial cuts and bringing the sites in Oxford, Cowley, Abingdon and Banbury together would save money.
Dr Harris said: "The minister acknowledged that there was a real question over whether the Home Office property people had ever done an adequate search of the area for better sites and also whether the probation service had settled on Trajan House too early in the process".
Local resident Matthew Savage said: "I am very pleased that we were given the assurance not only that the lease on the building in Mill Street would not be signed by the government for the time being, but that the Home Office would conduct a proper search for alternative sites. "
County Councillor Alan Armitage who attended the meeting, said: "The challenge is now to identify the better site which will produce a win-win situation all round for the probation centre and the community."
A Ministry of Justice spokesperson said: "It was a productive meeting where it was agreed that Thames Valley Probation will host an exhibition to engage with the public on processes and to provide information.
"We will continue to examine sites in Oxford and have agreed to look into those suggested within the required timescale."