Campaigners against a proposed eco-town near Weston-on-the-Green have received pledges of support from surrounding villages.
Representatives from 13 towns and villages, including Kidlington, Woodstock, Islip, Wendlebury and Bicester, attended a public meeting, organised by the newly-formed Weston Front Action Group.
More than 100 people attended the meeting on Wednesday, which was followed by a second meeting attended by 175 Weston residents.
Villagers expressed concern about the plan for a 15,000-home town on farmland close to the A34-M40 junction, which is on on a Government shortlist of 15 potential eco-towns.
Weston resident Tony Henman, who chaired both of the meetings, said he was delighted with the level of support.
He said the developers, Parkridge Holdings, had still not started consultation with local people, despite fears there could be a Government decision on the eco-towns as early as the summer.
Mr Henman said afterwards: "The developers are being coy about what they want to do. Our resolution is to raise funds so we can instruct planning experts. There is a real possibility of judicial review proceedings in the future.
"People are horrified by the traffic implications of this scheme.
"Nobody seems to support it, apart from the developers and a few local landowners."
Parkridge has pledged to invest in public transport, including helping to pay for the East-West Rail Link, between Oxford, Bicester and Milton Keynes.
A spokesman said: "Over the next few months, Parkridge will be working closely with the relevant public bodies, local authorities and members of the community to develop the proposals further.
"Parkridge aims for the proposals to be exemplary in terms of protecting the environment, reflecting the needs of the local area and its existing communities and in the delivery of innovative public transport, as well as delivering much-needed housing."