Campaigners behind Keep Frome Local have called on the pro-supermarket group Frome for All to work with them for the benefit of the town.

Luke Wilde, the chairman of the Keep Frome Local group which is against a large supermarket on the Saxonvale site, said the groups should not give the developers the advantage of seeing the town's residents being divided.

He said: "We cannot give the developers the advantage of a divided Frome. The more polarised the opinions expressed and the more the argument deviates from the hard facts, the more control we hand over for the future of our town.

"Those in support who are following our Facebook and Twitter campaigns are keen to see the two groups combine efforts – a sentiment also reflected in many letters published in the Somerset Standard."

Mr Wilde said there was a lot of similarities between the two groups but that they wanted clarity from the founder of Frome for All, Michael Rhodes, about where he stands on the Mendip District Council development brief.

He said: "We feel there are similarities in the campaigns of both Keep Frome Local and Frome for All – if we could just understand where Michael Rhodes stands on the planning brief, we could then move forward. We also want to know where Councillor Nick White, stands – is he in support of the brief?

"I think we're all in agreement that this debate needs to move forward and there is a potential for agreement."

Keep Frome Local was formed in December 2010 in response to proposals by the Tesco-favoured London-based developer St James Investments, to build a retail park on the Saxonvale site comprising a 40,000sq ft supermarket and a 40,000sq ft of retail.

Mr Wilde said the general consensus of various public meetings was that hundreds of Frome people support the district council's brief on how it wants the site to look.

He said: "The brief document involved massive local input, and a lot of hard work. It has been regularly re-approved by the district and town councils since it was first published.

"It meets most of the requirements that Councillor Nick White and Michael Rhodes seem to want; a good range of shops, and the kind of new town centre development they say local people are in favour of."

Mr Wilde said the brief does allow for a supermarket, but one of about 16,000sq ft – not the 40,000sq ft proposed by St James Investments.

He said: "We believe a bigger supermarket would have a catastrophic effect on traders in the centre of Frome, and bring massive problems with traffic."

He said: "The brief is supported by Independents for Frome councillors such as deputy mayor Pippa Goldfinger, Peter Macfadyen and Graham Burgess. This position also seems shared by Liberal Democrats district councillors, including Sam Phripp."

Barry Campbell, a member of the leadership panel of Frome for All, said the group would work positively with others if there was common ground.

He said: "Frome for All is an independent group. We do not see ourselves as 'the official opposition' to other concerned groups.

"We want to encourage developers to bring forward a high quality town centre development that integrates well with the existing town centre.

"One of our main priorities is to enable as many local people as possible to shop in their own town centre and reduce over-reliance on out of town stores and trips to other towns.

"We think this is best served by the approach and views that we have been advocating and would be undermined by insisting on only a small town centre supermarket.

"Once there is a planning application it will be possible to see where different community groups have common ground and where there may be differences. We will work positively with others on areas of common ground and respectfully where there may be differences.

"We recognise that the Saxonvale development brief will be a significant factor in the consideration of any planning application and that there should be additional public consultation in relation to any proposal."