From Longman Dictionary of Contemporary Englishan uphill struggle/battle/task etcan uphill struggle/battle/task etcsomething that is very difficult to do and needs a lot of effort and determination → uphill
Examples from the Corpus
an uphill struggle/battle/task etc• Rehabilitation will be an uphill struggle.• Unless you have a goal your learning will be an uphill struggle.• Voice over Police are hoping to trace original owners but admit it's an uphill task.• While critics of his decision gained momentum Thursday, the record shows they face an uphill battle.• It proved to be an uphill struggle, and was far from successful.• However, each parlor faces an uphill battle because the city hired a financial consulting firm to review the applications.• Smith said gay-rights advocates still believe they are fighting an uphill battle in opposing the bill.• Kopp said he faced an uphill battle in winning approval for the bill. 