The phrase "a damaging setback" is correct and usable in written English.
It can be used to describe an event or situation that causes harm or hinders progress.
Example: "The unexpected loss of funding was a damaging setback for the research project, delaying its completion by several months."
Alternatives: "a significant obstacle" or "a serious hindrance."
This race was a damaging setback for the hard right.
But it still felt like a damaging setback; a point of no return.
Only assertive, sustained American diplomacy is likely to keep the conflict from turning into a ruinous ordeal for both Israelis and Palestinians and a damaging setback to American interests in the region.
A European parliament source said "overwhelming opposition" from ALDE MEPs had forced Verhofstadt to take the idea off the table, a damaging setback as he runs for president of the European parliament.
Tottenham's stuttering Premier League form continued as their challenge for a top-four sufferedfered a damaging setback with defeat at home to Norwich.
The overly broad scope of the secret subpoena and the lack of notification to the AP by the Justice Department represent a damaging setback for press freedom in the United States.
For a rogue nation that prides itself on threatening the world community, membership in the Axis of Evil is considered essential, which makes North Korea's expulsion from the group a particularly damaging setback.
But the more damaging setback has been a strained relationship with Coach Rick Pitino, who has grown weary of his talented point guard's swagger and shoot-first mentality.
The DTI Inspectors' report was the most damaging setback Maxwell ever suffered.
Dundee suffered another damaging setback in their battle to avoid relegation by slumping to at the hands of Aberdeen.
Only weeks after he entered the Elysée, Hollande, 58, suffered his first damaging setback – and considerable ridicule – when first lady Valérie Trierweiler, 48, used her Twitter account to support Royal's rival in the June 2012 legislative elections.
