David Trimble has a good track record with the council. It was this body which elected him four years ago. It was a surprise at the time, but not only did they choose him, they have stood by him.
Indeed last year, he received their overwhelming backing for his decision to sign the Good Friday Agreement.
Now he has another battle on his hands - selling George Mitchell's Review proposals.
It's impossible to predict what the result will be, but the Ulster Unionist form-guide makes for interesting reading.
Within the Assembly group, Mr Trimble does have a strong majority in favour of the proposals
But at Westminster, his fellow MPs have already indicated that most of them are opposed to the party leader's strategy.
Final say
Among the 14 Ulster Unionists party officers, it's believed there is a majority who back the deal.
But all sides now know it will be the party's council which will have the final say.
When they met last year to decide on the Good Friday Agreement feelings ran high.
The council is the most important and also the largest grouping in the party
Of the 860 members, 120 represent the Orange Order. Assembly members, MPs and councillors make up a complement of 90.
The vast majority, 650, are delegates from the constituency associations.
So how does the voting system work?
Senior Ulster Unionist James Cooper acknowledges that the members of the council will come under pressure from different sources over the coming week but insists: "The delegates are free, there is no such thing as a block vote per se."
The council will meet at the Ulster Hall in central Belfast on Saturday next. This is the same venue where David Trimble was elevated to the party leader's position.
It is also the location where the Ulster Unionist Party held its first meetings almost 100 years ago.
Whatever decision is made next week, it is likely to be one of the most important made by the party's members in its history.