The phrase "a prime purpose" is correct and usable in written English.
You can use it to emphasize the main or most important reason for something.
Example: "The prime purpose of this initiative is to improve community engagement and foster collaboration among residents."
Alternatives: "a primary goal" or "a main objective".
A prime purpose appears to have been to hack into the Gmail user accounts of Chinese human rights activists.
A prime purpose, according to the draft, is to "prevent, combat and eradicate the illicit trade in conventional arms and their diversion to illegal and unauthorized end use".
A prime purpose, according to the treaty's latest draft, is "the need to prevent, combat and eradicate the illicit trade of conventional arms and to prevent their diversion to the illicit market and for unauthorized end use".
She said the material was "highly inflammatory when our country is currently engaged in a war against terrorism in Afghanistan, a prime purpose of which is to arrest Osama bin Laden".
Even the World Health Organization, the United Nations agency who has as a prime purpose to "direct international health efforts, tackle epidemics and help in emergencies, (has been) badly weakened by budget cuts in recent years," the New York Times reported September 3.
A financial services company is a business whose prime purpose is to increase its revenue.
The leader of a party whose prime purpose is to break up the Union seems the one politician who most offers a conciliatory message of how partnership can work in politics.
A political party's prime purpose is to develop positive policies for the betterment of the country.
According to a recent survey, the prime purpose behind the German co-operatives is not to make shareholders rich but to promote renewable energy and to keep money in the local economy.
If the prime purpose of a food system is to nourish people and keep them healthy, this one is failing.
So the prime purpose of a bond system would not be to make it easier to meet the migration target, but to close off an illegal route.
