A new group has launched a campaign to stop thousands of houses being built in the countryside.
The Greenfield Guardians group is encouraging people to object to plans for 500 or more houses to the west of Burgess Hill.
It also wants residents to lobby West Sussex County Council to maintain a gap between the town and surrounding villages to stop them merging into one urban sprawl.
The group fears the building could lead to the creation of a super-town by linking Burgess Hill with Hurstpierpoint, Sayers Common, Albourne and Hickstead.
Founding members Michael Nailard and David Evans said the group was opposed to the proposals of the council's draft structure plan.
They were also firmly against plans from a developer to build as many as 3,500 houses in Burgess Hill during the next ten to 20 years.
Mr Nailard, of Chestnut Grove, Hurstpierpoint, said: "We have been watching the gradual erosion of our rural environment with progressive building development for many years with growing alarm.
"They the proposals would reduce the countryside between Burgess Hill and Hurstpierpoint to a narrow strip and ultimately merge the surrounding village settlements.
"We feel totally appalled at the loss of this beautiful wooded countryside, which is enjoyed by the residents of all the surrounding settlements, so we have joined forces and created an action group to oppose the planned destruction."
Mr Nailard said the group's aim was to stop any development and safeguard the rural identity of communities. It had applied to the council for a formal strategic gap to be marked out between Burgess Hill and surrounding villages.
He said: "We have been overwhelmed by the level of support given to us by residents of all the settlements, who are equally alarmed by this development proposal.
"But, however hard we push for the removal of the housing threat and the creation of a gap, it rests to a large degree with the number of housing protest letters written by residents to the council.
"If we achieve the result so many people want and the countryside to the north of Hurstpierpoint is saved, it will fully justify the time commitment the campaign has inflicted on our busy lives and the hundreds of pounds it has cost us.
"The issue is of such fundamental importance to our lives and those of the other residents who have declared their support that no effort is too great."
A council spokeswoman said: "Strategic gaps are agreed with district councils and there are very strong county council policies to protect them. We are determined to keep settlements separate.
"To the west of Burgess Hill there is an area which is not in a gap. It is low grade agricultural land and is not an area of outstanding natural beauty."
A report released by the council in November said planners would safeguard strategic gaps between towns and villages to prevent a sprawl.
Councillor Tex Pemberton said: "In the new structure plan we are looking at previously developed land first and then at the creation of urban extensions if we need to use greenfield land.
"We must be as flexible as possible on finding places for new development which do least damage to our environment.
"This means making hard choices and some gap boundaries may need to be reviewed. However, new development will be expected to make a positive contribution to enhancing strategic gaps.
"Make no mistake about it, our strategic gaps are here to stay. Development will not be allowed to swallow them up."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article