Как по Английски будет contre-démontrer

noun

A public demonstration organized in order to express opposition to the aims of another demonstration.

Примеры использования:

An effort to organize a counterdemonstration failed

verb

To hold a protest expressing opposing views to another protest, often at the same time and place

Примеры использования:

It's possible people from elsewhere could come to the town to counter-demonstrate., several groups …