HONG KONG — The Hong Kong government calls it national education. But parents, teachers, and pupils in the former British colony call it ‘‘brainwashing’’ and fear it is a ploy by Beijing authorities to indoctrinate the city’s young into unquestioning support of China’s Communist Party.

Plans by the government to introduce the classes have triggered mass protests and hunger strikes, the latest sign of the widening gulf between Beijing and the freewheeling semi-independent southern Chinese financial center, 15 years after Britain handed it back to China.

The dispute deepened as classes started this week, with activists including a handful of hunger-strikers camping out in front of Hong Kong government headquarters in a bid to force officials to drop plans to introduce the subject in primary and secondary schools.

They have been joined each evening by thousands of protesters wearing black. A local television station fanned the flames when it called the activists a ‘‘destructive faction’’ controlled by London and Washington.

The protesters are afraid of what they see as underhanded attempts to indoctrinate the city’s next generation with Beijing-style nationalist education classes used in schools all over China to inculcate support for the Communist government.