The most difficult issue was Ireland.
One London traders' representative calls this "the single most difficult issue" in implementing MiFID.
The estate tax could prove to be the most difficult issue for the committee.
"My other principle is to start not with the most difficult issue, but to start with easier ones," he continued.
Perhaps the most difficult issue concerning the relation between morality and belief in God is the problem of evil.
This is perhaps the most difficult issue in the debate about homeopathy; there are obviously reasonably good arguments either way.
"Yes, I think there will be peace in the region; yes, Jerusalem is the most difficult issue," Mr. Clinton said.
But the most difficult issue remained providing health insurance coverage to people who have lost their jobs.
He said: "Even on the most difficult issue of welfare, we have agreed to work together to find a solution.
The most difficult issue will be the future of the Halewood factory in Liverpool, where the Land Rover Freelander and the Jaguar X-type are made.
Both sides warn there are several hurdles to be cleared before a deal can be struck, with his demand for restricting EU migrants' benefits the most difficult issue.
