A test of wills opened up today between Assembly members and Secretary of State Peter Hain over the question of "who runs Stormont?"
The all-party business committee has decided to hold two full plenary sessions of the new Transitional Assembly next week.
But Mr Hain retains the legal power to forbid Assembly meetings.
On Monday the parties are set to debate his perceived role in the supposed nomination of First and Deputy First Ministers last week, with DUP leader Ian Paisley rejecting designation in the Assembly chamber.
And on Tuesday MLAs want to hold a long-delayed debate on the review of public administration including the shrinkage of the province's 26 councils into seven.
Ulster Unionist leader Sir Reg Empey said today it was time for "the control freaks of the Northern Ireland Office to let go".
Mr Hain repeatedly refused permission for the Assembly to meet earlier this year, in part because Sinn Fein was boycotting debates which it viewed as a distraction from the main business of restoring devolution.
It is understood Sinn Fein has reserved its position on whether it will attend the prospective debates next week.
It was envisaged the new Assembly would have greater autonomy.
But, as revealed in the Belfast Telegraph earlier this week, Mr Hain overturned a business committee decision by instructing the speaker Eileen Bell that Martin McGuinness should be allowed to speak in accepting his nomination last Friday.
Sir Reg said today: "It's basically about interference by the Secretary of State - first we had his intervention over the question of Martin McGuinness being able to speak.
"Then secondly, what is perceived to have been direct involvement in the language that was to have been delivered both by Ian Paisley and Martin McGuinness and the Speaker's response.
"But there is also the wider issue that earlier this year Mr Hain dominated proceedings, vetoed business committee decisions. Is it any wonder we have little credibility with the community if minor matters have to be determined by a Cabinet Minister?"
The UUP leader said mechanisms in the new Assembly were supposed to have changed and the Secretary of State could still prevent next week's sessions.
"In theory Mr Hain has a veto and this is actually going to test this. Is he going to use his veto or allow us to conduct our own business?"
He said Sinn Fein also had to be put to the test because if the party failed to appear it would send out a very negative message.
"The first thing Sinn Fein did in the new Assembly was to run bleating to Hain to encourage him to use his powers to allow McGuinness to speak. Sinn Fein ran to mammy to get him to wipe away their tears," Sir Reg added.