Campaigners against a proposed Jewish religious boundary (eruv) in south Manchester say they have 120 people who have declared their opposition to the plans, which would “only benefit 12-15 families”.

In signs of increasing local tension, an electronic petition set up by campaigners from South Trafford Against The Eruv was disabled by site administrators last week, after “inappropriate content” was posted.

An eruv is an area enclosed by a symbolic and physical boundary – often marked by thin nylon wire from poles – that allows Orthodox religious Jews to carry or push items on Shabbat, which would otherwise not be permitted. Supporters say this can include pushing people in wheelchairs.

The 13-mile eruv, which would be the country’s second biggest if it gets the go-ahead next month, would take in the wealthy areas of Hale and Hale Barns, and parts of Timperley and Altrincham. Suburbs with a large Jewish population, these areas are to the south of Manchester, in Cheshire.

The protest group, which includes Jewish residents, said the boundary would have a detrimental effect on “social cohesion, in times when religious privilege could lead to hatred and factionalism within the community”.

They added that the “majority of the Jewish community in the area are opposed to this proposal as they prefer to live peacefully in our diverse community”.