An attempt by one of the United Synagogue's newest communities, Hadley Wood, to extend its premises is being blocked by Enfield Council.
The congregation started as a satellite of Cockfosters and North Southgate Synagogue in 1990, becoming a fully-fledged US member 10 years ago. Since 2002, congregants have gathered in the ground floor of a house purchased as a meeting place. Its first rabbi, who arrived in 2003, lived upstairs.
In 2013, a planning application was submitted to Enfield for a front and rear extension. This was withdrawn after the community was told it required a "certificate of lawful development" to officially register the property's change of use.
To acquire a certificate, Hadley Wood had to prove that the building had been used primarily for religious gatherings for at least 10 years.
But the council ruled in autumn that the community had not produced sufficient evidence to support its application.
The congregation has now appealed to the Planning Inspectorate.
Hadley Wood chairman John Melchior said that "a hearing is to be held in June at which we are very much hoping for a positive outcome".
The congregation has 240 members and regularly attracts up to 50 to Shabbat services.