Two Reform synagogues in the Harrow area have taken the first steps towards a potential merger.
Members of the Kol Chai community in Hatch End and the Middlesex New Synagogue have been invited to parallel open meetings on March 21 to discuss the option.
The idea is for the buildings to be sold to fund a purpose-built site for a combined adult membership of 1,300.
Kol Chai co-chair Neil Mendoza said: "Our area is an exciting and dynamic place to be Jewish. Harrow has the third largest Jewish population in London and Bushey is one of the fastest growing communities in the UK.
"We are determined to ensure that there is a strong, dynamic Reform Jewish community in this area, both to invigorate our existing members and to attract the many unaffiliated local Jews."
Middlesex New chairman Harry Grant added that "the ability of both our communities to continue to appeal to new and existing members is severely limited by the location and size of our respective buildings, and by the changing profiles of our memberships.
"However, we will only move forward with the support of our two communities.
"No decisions have been taken - except to recognise that doing nothing is an unattractive option."
Both Middlesex New's Rabbi Kathleen de Magtige-Middleton and Kol Chai's Rabbi Michael Hilton say they are keen to explore the possibility of forming a ministerial team.