Parents in Terenure want a new Educate Together school for their area - and they have 800 children lined up to enrol.
Mum-of-two Nikki Murphy set up the Terenure Educate Together Start Up Committee in May when she failed to secure a place for her eldest son in any local schools.
Despite applying to nine schools for a place for four-year-old Reuben for next month, he was not offered a place anywhere.
That means Nikki has had to postpone his start in school until he is five.
"The situation is urgent - we need a new school in the area," Nikki said.
Parents have been registering expressions of interest from Terenure, Templeogue, Rathmines and Harold's Cross for an Educate Together school.
The non-denominational ethos of the school is attractive to many parents, Nikki said. She added that parents of "all religions and none" have signed up to ask for a new school.
In June, the group met with Minister for Education Jan O'Sullivan, which Nikki said was "a very positive" meeting.
The department will make a decision next month as to whether the area is suitable for a school.
"We are very optimistic because we have shown her the demand that was also shown in the department's own survey in 2012," Nikki said.
The group hope that they will be able to secure a new Educate Together school in the locality by September 2016.
A spokeswoman for Educate Together said that the appetite across Dublin for the schools was "undeniable".
In the Dublin 6 area, in particular, the fact that 70 children had registered this month was a "key indicator", she said.
"Because the Dublin 6 expression of interest list opened after the enrolment season for other schools ended, these parents will more than likely have school places for their children, but they prefer Educate Together in the area," she said.
Interested parents can register at: www.educatetogether.ie/dublin-6