The phrase "an overriding challenge" is correct and usable in written English.
It can be used to describe a significant or dominant difficulty that takes precedence over other issues.
Example: "The team faced an overriding challenge in meeting the project deadline due to unexpected technical difficulties."
Alternatives: "a primary obstacle" or "a major hurdle."
Patient adherence to treatment recommendations was viewed as a significant, often overriding challenge for cardiologists.
But even if the world achieved that goal, the report said, "the epidemic would remain an overriding global challenge for decades".
"David Cameron is marooned between a party that wants a referendum as a proxy for exit and public who I think understand that the overriding challenge for Britain is to deliver investment, jobs and prosperity".
The overriding challenge is that it would take astronauts more than a year to get there, so they'll have to take everything they need or have it waiting for them along the way, said Jason Crusan, director of NASA's Advanced Exploration Systems Division.
For Colombia, the overriding challenge is to provide security for all its citizens replacing legalism and extra-legal violence with the rule of law.
"The overriding challenge facing the I.R.S. is that its workload has grown significantly in recent years, while its funding is being cut," said Ms. Olson, who called for streamlining the tax code and increasing the agency's budget.
Taking as its starting point the proposition that 'achieving sustainable development will be the overriding challenge of this century', the report calls for 'a new era of change', including on the parts of government, the UN system and the private sector.
But the simple fact is that the overriding challenge we face is winning back the Presidency in 2012 and we will not accomplish that objective unless there is dramatic change in the way the RNC does business.
INDEED, Vonage acknowledges that it has two overriding challenges.
She was able to weather the challenges of these transitions thanks to an overriding sense of pragmatic optimism.
"It's an overriding passion, not just for the music [but] for the challenge," reckons Lucy Parham, the leading concert pianist who taught Rusbridger his Chopin.
