For pre-school operator Francis Ng, the manpower crunch in the industry is so severe that his centre managers have had to stand in for the teachers.

The 49-year-old founder of childcare centre chain Carpe Diem, which has 25 childcare centres islandwide, said the sector has always faced a shortage of qualified teachers, but this is the worst he has seen in his 11 years in the business.

"It started about two to three years ago, when there was a sharp increase in the number of centres being set up," said Mr Ng. "That requires a huge supply of teachers but when that isn't met, everybody is rushing for the same pool of teachers."

In the past, Mr Ng used to get up to 10 interested candidates when he placed an advertisement, and could take his time to pick one. But these days he often gets hardly any responses for weeks.

"Now, we really have no options. Whoever is qualified, we just take them in. If we wait and contemplate, somebody else would have taken them already."

He added that he had to scrap one of his "price guarantee" programmes - which meant parents would not be affected by any fee hikes - because the staff costs were getting too high.

"I feel bad but it is something that's inevitable...Currently, a lot of operators are raising salaries so school fees have also gone up."

Mr Ng said a pre-school teacher with a diploma could command a monthly salary of about $1,800 three years ago but this has now jumped to at least $2,300. A centre manager used to earn about $2,500, he added, but this has gone up to about $3,500.

In addition, he slows down enrolment when new childcare centres are opened, so that there is time to hire teachers and to let the children settle down.

Retaining staff is also a challenge now because of the competition, and because teachers have more choices.

To keep his staff, Mr Ng uses incentive programmes such as quarterly bonuses and subsidised overseas trips, but even these are not enough.

"Salaries are more tangible, so people still leave," he said. "It's more unpredictable now. This is going to be an issue for the next few years."