The push to secure enough Jewish secondary school places in north-west London gathered pace this week as a second group revealed its ambition to launch a new school.
It follows last week's announcement that a private trust plans to open a Jewish free school, Kedem High, in the borough of Barnet next year.
Eve Sacks, one of a group of a dozen parents who met on Tuesday, said they were exploring an alternative model to Kedem.
She said: "We are committed to a modern Orthodox school with an open-minded outlook and a robust Kodesh (Jewish studies) that will provide an inspiring Jewish education.
"We want to hear what parents have to say. We would prefer a collaborative, grassroots effort to leaving it to a consultancy to set up a school."
Kedem is projected to be a Zionist, mainstream Orthodox school under the aegis of the Chief Rabbi. It was founded by Andrew Rotenberg - the chairman and principal of the Rosh Pinah primary in Barnet - in partnership with education company Lilac Sky.
Mrs Sacks - who was involved in a group last year trying to help parents who could not find school places for their children - said they had previously put their own plans on ice pending research by the Partnership for Jewish Schools (Pajes) to gauge demand for a new school.
Pajes leaders said this week that they had been "surprised" at Kedem's decision to go public on its plans before completion of the research.
Pajes chairman Jonathan Goldstein said: "We would have expected to have at least discussed this quietly before it was read on social media."
But he added that Kedem's backers had now "agreed to work with Pajes to assess the need going forward".
Pajes chief executive Rabbi David Meyer disclosed: "There are a number of different groups that have approached us with an interest in setting up a free school that were willing to put it on hold subject to the findings of our review.
"They were a little bit upset to find that somebody then takes unilateral decisions."
Pajes has reserved judgment on whether a new school is necessary but is urging a "collaborative, consultative" approach involving other schools.
"To open a school to the detriment of other schools would be a disaster for everybody," Rabbi Meyer said.
More than one secondary was looking to offer more places, he said, but warned that any decision may depend on local councils rather than the schools.
Mr Goldstein said that, while Pajes agreed that extra places needed to be created, the question was how best to achieve that. A meeting of all the current secondary schools, together with the Kedem trust, will take place later this month to discuss the issue. Pajes will report on its findings during the summer.
The crunch time for places is likely to be after July 2018 with a larger number of children due to graduate from the capital's Jewish primaries.
"Our priority is to ensure, over the medium to long-term, that every Jewish child who wants to be in full-time Jewish education has a place at a Jewish school," Mr Goldstein said.
Kedem's leaders were anticipating around 400 people would attend its own public meeting last night to discuss its plans.
Mr Rotenberg said: "If other schools had announced that they would be expanding to meet the additional demand, then we would not have needed to do this."
He said that Kedem's trust was "currently in discussions with Pajes to find a solution and are happy to discuss any other proposals that address the underlying problem".
