The phrase "a protest which" is correct and usable in written English.
It can be used to introduce a clause that provides additional information about the protest being referenced.
Example: "The protest which took place last week drew thousands of participants advocating for climate change action."
Alternatives: "a protest that" or "a demonstration which".
The shirt of a Bahraini protester who was killed by live fire at a protest, which was part of the brief exhibition at the so-called "Museum of Revolution".
The Braves filed a protest, which was quickly denied.
In many cases people protesting against the conditions they are being held in, a protest which is a non-violent and legitimate expression of dissent.
As a result of this scene, which ought never to have happened, Hayes, the American, entered a protest, which was upheld by the judges and he was awarded the race.
Yet from this bowel of extreme isolation Ashker helped orchestrate a protest which united black, latino and white prisoners in a massive hunger strike – 32,000 inmates in 33 Californian prisons – which shook the penal system.
California's governor, Jerry Brown, has gone on vacation, denting hopes of a quick resolution to a protest which has united black, Latino and white inmates, including members of racist gangs.
Being disqualified from service for voicing your political opposition is a form a personal protest, which is really all you can do in this situation (without misleading the court and mangling the procedure).
We have a responsibility to deliver a safe protest which protects residents, tourists, commuters, protesters and the wider community.
The Portland Trail Blazers support of marriage equality sparked a Westboro Baptist Church protest, which itself attracted a counter-protest.
In 1989, Merullo responded with a heartfelt protest, which Royko featured in a column.
Workers at a subsidiary of Fnac, a retailer, used a blog to rally support and gather evidence for a redundancy protest, which they then took to employment tribunals.
