The Education Ministry is committed to providing independent schools with the resources they need to challenge and teach their students a sense of service, Education Minister Heng Swee Keat told Parliament on Monday.

Independent schools "play an important role in exploring new approaches of developing and stretching students with a strong academic foundation," he said, in his first comments on funding changes for independent schools since The Straits Times first reported on them two weeks ago.

Mr Heng also gave the assurance that independent schools will remain open to all students, adding that school fees for these schools have not increased this year, and that MOE will ensure that fees remain affordable.

He was responding to questions from MPs Edwin Tong (Moulmein-Kallang GRC), Lim Biow Chuan (Mountbatten), Ang Wei Neng (Jurong GRC) and Non-Constituency MP Yee Jenn Jong.

Mr Heng explained that his ministry had conducted a review recently to assess if independent schools are resourced appropriately, taking into account factors like the higher overheads in schools with smaller enrolments. The main reason for the review, he added, is that "schools with higher enrolment can spread their overheads better, while schools with lower enrolment cannot enjoy the economies of scales."

He emphasised that more schools are receiving higher funding, as a result of the review. Six out of 10 independent schools received up to 5 per cent more funding, and only four had their funding cut this year by no more than 3 per cent.

Although schools which have students who are both in the gifted education programme and the integrated programme will now only receive funding for the former, Mr Heng said that students will not be negatively affected as one programme grant is enough for their development.

As part of the review, he said, MOE had discussed with independent schools how they can use their resouces in a more cost-effective way, for instance through the judicious use of air-conditioning.

He added that while the ministry welcomes the strong school alumni support, fund-raising must not become a burden and deter students from less well-off backgrounds from applying to these schools.

"Our aim is to ensure that we continue to pursue excellence at all levels, regardless of where the students are - it is never to level down," he said.

The Ministry of Education has significantly increased its investment in education across all levels and schools in the past decade, he said. The per capita cost of educating a primary school student more than doubled from $3,600 in 2004 to $8,700 in 2013. The per capita cost of secondary education almost doubled during the same period, from about $5,700 to $10,800.