Some of the schools that are likely to take the route include Anglo-Chinese School (Primary), CHIJ St Nicholas Girls', Nan Hua Primary and East Spring Primary.

These schools had 100 vacancies or fewer after the latest stage of registration ended on Tuesday.

The balloting is part of the seven-stage annual registration process for Primary 1 that kicked off on June 30.

In this system, those with higher priority get to register earlier. The first stage of registration, for example, was open to siblings of pupils already enrolled in the school. The last stage will be for foreigners who do not have Singapore permanent residency status.

During the next few phases, if the number of applicants exceeds the places available, priority will be given to those who live close to the school.

Registration for the next phase, 2B, starts today. This phase is open to children whose parents had volunteered at the school for at least 40 hours. It is also open to parents who are members of a church or clan associated with the school.

Popular schools like CHIJ St Nicholas Girls' have been getting calls from anxious parents.

It has a waiting list of 22 children whose parents either have no connections with the school or live more than 1km away, said principal Chan Wan Siong. Last year, it had 256 applications for 210 places in total.

Over at Nan Hua Primary, the children of 36 parent volunteers and 31 grassroots leaders are eligible for Phase 2B, said principal Lee Hui Feng.

However, the school has just 27 places on offer in this phase.

Last year, it received 273 applications overall for 240 places.

Registration for Phase 2B ends tomorrow and the results will be announced next Wednesday.

For more information on the number of places on offer at each school, visit www.moe.gov.sg/education/admissions/primary-one-registration/vacancies/