Opponents of the location of the Etz Chaim free school in Mill Hill have issued judicial proceedings against Barnet Council.
The protesters claim the council ignored the needs of the elderly and disabled when granting planning permission for the conversion of a former garden centre into the school's permanent premises.
Local Jewish disabled resident and campaign group leader Daniel Coleman described the case as a "landmark legal action under the Equalities Act 2010".
Etz Chaim governors' chair Adam Dawson declined to comment on the latest development. However, he has apologised to local residents concerned over the erection of concrete security bollards at the entrance to the Daws Lane site.
"These were installed by mistake while I was away during the festival period and I am assured that they are to be removed immediately," Mr Dawson said.