Ulster Unionist leader Sir Reg Empey has accused the NI secretary of interfering too much in the running of the assembly since its recall in May.
Sir Reg said people were "playing politics"
Speaking on the BBC's Inside Politics, he said Peter Hain should have left the local parties in control.
"People are playing politics with the secretary of state, trying to push him one way or the other," Sir Reg said.
He said this was happening because those people "maybe don't want to take their own decisions".
The Ulster Unionist leader said that this was "wrong".
"I believe if he (Mr Hain) hadn't been involved in it in the first place, and it had been left to the speaker and the business community to set the business, the business would have been set and the assembly would have met far more frequently and done far more business," Sir Reg added.
On 15 May, Northern Ireland's politicians took their seats in the Stormont assembly for the first time since its suspension in October 2002.
It has only met a few times since May after its failure to elect a first and deputy first minister.
A cross-party Preparation for Government Committee has been formed, but progress has been slow.
Talks are expected to continue until August, with intensive efforts resuming in the autumn.
If attempts to restore the assembly fail, the two leaders say that in December there will be a "prime ministerial summit to launch new British-Irish partnership arrangements".
The government confirmed the next assembly elections would be postponed until May 2008 if the executive is restored by this date.
Devolved government was suspended over allegations of a republican spy ring. The court case that followed collapsed.
Direct rule from London was restored in October 2002 and has been in place since.