HONG KONG — This summer, Hong Kong has seen protests against the government by students, teachers, parents, lawyers, doctors, nurses, social workers, seniors and finance workers. On Friday, members of one prominent group that has not yet collectively taken to the streets are expected to join them: professionals within the government itself.

The action by members of the civil service — scheduled to be a two-hour gathering after work in a downtown park — is likely to be one of the more placid protests in this former British colony. But it could also be a powerful one, showing that public discontent with Hong Kong’s leaders is shared by at least some of the people who serve under them.

It comes as the government, led by Chief Executive Carrie Lam, is facing pressure from Beijing to restore order, in light of increasingly frequent clashes between demonstrators and the police. This week, the People’s Liberation Army garrison in Hong Kong released a promotional video pledging to defend Chinese sovereignty in the semiautonomous territory, with footage of troops rounding up mock protesters in a drill.

The planned demonstration by city employees has raised questions about whether such an action would violate the civil service’s restrictions against public engagement in politics, and how it might affect the service’s reputation as one of the region’s most effective bureaucracies. In a message sent Thursday to all civil servants, the official who oversees them, Joshua Law, said he “absolutely” did not approve of such a demonstration.