Martin McGuinness has said he has no problem signing up to a pledge of office with Ian Paisley before 24 November, but it depends what is in it.
Martin McGuinness could become shadow deputy first minister
However, Sinn Fein's chief negotiator added that the pledge could not impact on the party's internal debate.
The DUP wants a pledge of support for policing in place before Mr Paisley and Mr McGuinness can become shadow first and deputy first minister.
Mr McGuinness said: "It really will depend what is in that pledge."
He told the BBC's Politics Show on Sunday: "We will have to see at the end of our process a very clear situation where a Sinn Fein ard fheis will take place.
"For Ian Paisley to expect me to sign up to anything, prior to the membership of Sinn Fein having a say in all of this, is quite ridiculous. "
On Thursday, party president Gerry Adams said Sinn Fein would engage in a consultation process with its members on the proposals contained in the St Andrews Agreement.
Mr Adams was speaking in Dublin after attending a meeting of the party's national executive.
Mr Adams gave no indication of how long the consultation process would take. He also did not reveal when SF would call a special ard fheis on policing.
The Northern Ireland parties have been given until 10 November to respond to what the governments are calling the St Andrews Agreement.
It was published after intensive three-day talks between the parties at St Andrews in Scotland.
If all goes to plan, a first and deputy first minister will be nominated on 24 November and the devolved institutions will be up and running by 26 March.