"unrelenting criticism" is correct and usable in written English.
You can use it when you want to describe an intense and continuous criticism or disapproval. For example, "The President faced unrelenting criticism over his response to the pandemic."
Yet the Mormon Church has also faced unrelenting criticism over its origins in Palmyra.
In Portugal's first two matches at the European Championships, Ronaldo had accumulated no goals, only unrelenting criticism and taunting comparisons to Lionel Messi.
Bulgaria joined the European Union in 2007 and has faced unrelenting criticism by the European Commission for failing to fight corruption and reform its ineffective justice system.
James, the company's London-based chief operating officer who has been the focus of unrelenting criticism in Britain, said he was declining his $6 million bonus.
Triggs has faced unrelenting criticism from members of the Turnbull government, which began with political attacks on its 2015 report into children in immigration detention.
Radcliffe, 34, the world-record holder, dropped out of the 2004 Athens Olympic marathon at the 22-mile mark and faced unrelenting criticism from the British news media.
Despite his unrelenting criticisms of many of Scotus' positions, William of Ockham's moral theology develops, rather than dismisses, the main lines of Scotus' ethical deliberations.
Evans stood down from Top Gear on Monday amid falling ratings and unrelenting newspaper criticism after he took over from Jeremy Clarkson on the BBC2 motoring show.
However, Evans quit in July after just one series amid falling ratings, unrelenting newspaper criticism and a breakdown of his relationship with LeBlanc.
Chris Evans has quit Top Gear after just one series in charge of the BBC2 motoring show amid falling ratings, unrelenting newspaper criticism and a breakdown of his relationship with co-host Matt LeBlanc.
Bloggers were unrelenting in their criticism of displaced restaurants, coffee shops and offices.
