Lee did not reveal what the landlord was now asking, but said some real estate agent friends told him their agencies had been asked to lease the floor at HK$75,000 a month - a 63 per cent increase.

He said the kindergarten's contract with the landlord would expire at the end of this month, but he was informed only in mid-June of the rent rise.

"We are very disappointed with the landlord's decision," he said. "We're looking for other premises, but in Hong Kong, it's a long and difficult process looking for an affordable venue."

The current annual tuition fee for the kindergarten's all-day classes is about HK$40,000, half of which is paid by the government with vouchers. There are now 30 children and four full-time staff. Lee said teachers were willing to accept a monthly salary of about HK$10,000 - 30 per cent lower than the market rate.

Marilou Lasam, a 41-year-old swimming pool supervisor, said although she had found another kindergarten for her three-year-old son and five-year-old daughter, she had to buy new summer and winter uniforms for them.

"I was very angry at first, because they told us so late," said Lasam. "My son just got into the kindergarten and my daughter has spent three years here. It's pretty sad that they're closing."

According to land records, the current owner of the floor is a company named Borneo, which purchased the site in 2007 for about HK$5 million.

The floor was also recently advertised for sale on the website of property agency Midland for about HK$25 million.

The advertisement had been taken down by the time the went to press.

According to an earlier survey by lawmaker Kenneth Chan Ka-lok, about 12 per cent of Hong Kong's non-profit kindergartens are renting private venues.