The phrase "a longstanding feature of" is correct and usable in written English.
It can be used to describe something that has been a consistent or enduring characteristic of a particular subject or context over time.
Example: "The use of renewable energy sources has become a longstanding feature of modern environmental policy."
Alternatives: "an enduring aspect of" or "a persistent characteristic of".
Counterterrorist cooperation has been a longstanding feature of the secret cooperation.
But with no public comparative data for years past, it is not clear whether that represents a change or just a longstanding feature of the war.
The rule is a longstanding feature of the traffic laws of the US stats of Idaho, where it is known as the "Iadho Stop".
A longstanding feature of sports such as rugby, the scheme had been trialled by the FA in the Auto Windscreens Trophy and found to be an effective antidote to bothersome behaviour.
A longstanding feature of the Law of Armed Conflict, which has been incorporated into the Army's Rules of Engagement, is the concept of proportionality: all military action must be necessary and proportional to a given threat.
In other written evidence, the Institution of Civil Engineers (ICE), which has more than 86,000 members, including students, argued that "low levels of productivity have been a longstanding feature of the UK's economy", falling well behind France, Germany and the US.
They plumped for the backpage spectacular that was "Have You Ever Ridden a Horse?"—a longstanding feature that got the biggest and best in the world of clubbing to answer a series of intentionally awful questions with often hilarious results.
Not every abuse victim dials 999, even though coercion, control and violence may be longstanding features of their relationship.
Remarkably, though, for such a longstanding and uniform feature of human biology, scientists are still not sure exactly what causes presbyopia or what might reverse it.
The dominant longstanding feature in the landscape (Figures 1 and 2) is central in creation records, chronicles of settlement, and ritualistic practises.
For a celebratory meal, jump in your car and drive up to La Jolla for a sunset dinner at California Modern at Georges on the Cove, a longstanding favourite featuring an extensive wine list of more than 400 selections from around the world.
