Hong Kong on Monday vowed to push ahead with patriotism classes despite mass protests over what parents and teachers call Chinese brainwashing.

Chief Executive Leung Chun-ying offered a new round of consultations with parents after up to 90,000 people protested against the plans at the weekend.

But he ruled out any delays to the implementation of the policy, which will see all primary and secondary school pupils taking mandatory "national education" classes by 2016.

"There will be a three-year starting period. This means that schools, depending on their own situation, can decide to start teaching the subject this year, next year, or the year after the next," he told reporters.

The government has said the subject is important to foster a sense of national pride and belonging, but many teachers, parents and students complain it forces children to learn Chinese communist propaganda.

"The government definitely does not have the intention to brainwash," said Leung, who was chosen to govern the semi-autonomous southern city by a pro-Beijing committee earlier this year.

"Schools, teachers and educational bodies will have a lot of space using professional attitudes and using open methods to teach this subject."

The government announced the formation of a special committee to monitor the implementation of the subject following Sunday's mass protest.

The committee will ensure the subject is taught in a way "to educate our students to have independent thinking, to be able to analyse situations and come to an objective judgement", Chief Secretary Carrie Lam told reporters.

A leading parent group has publicly rejected the offer of further consultations with the government, saying their participation would only legitimise the process.

Under the proposed curriculum, which could be introduced voluntarily as early as September, students would take 50 hours of lessons a year focusing on "building national harmony, identity and unity among individuals".

Critics say the curriculum glosses over events like the bloody Tiananmen crackdown on pro-democracy protesters in 1989, and the mass starvation and extrajudicial killings of Mao's Cultural Revolution.

A 34-page government-sponsored booklet intended to be used in the classes praises the Chinese Communist Party as "progressive, selfless and united".

China's one-party rule is compared favourably to multi-party democracy as practised in the United States, which is described as inefficient and disruptive.