sore point ,
sore spot ,
sore subject

"It was a sore point in the Administration," the former official said.

Another sore point was the access that many of the program participants had to the top officials at the agency.

But even now language support remains a sore point, an official said.

He seemed to have no awareness of having hit a sore point dead on.

The issue is a sore point not just in France.

That's rather a sore point with me, as a matter of fact.

The plant has been a sore point for more than a decade.

Money has long been a sore point in the world of adult education.

Asked about it today, he chose not to return to what had been a sore point.

Safety officials' access to the Secretary has been a sore point in the department.