Uncertainty over who calls the shots in the DUP is threatening to leave efforts to restore Stormont in limbo, Sinn Féin has warned.
Party negotiator Conor Murphy questioned the authority of the DUP negotiating team, headed up by party leader Arlene Foster, that engaged with them in the last round of ill-fated talks.
Sinn Féin has claimed Mrs Foster agreed on a draft deal to resurrect powersharing last month before pulling the plug in the face of an internal revolt among party members angry at the prospect of concessions on the thorny issue of the Irish language.
It is an allegation Mrs Foster has strenuously denied.
Asked about the prospects of a re-engagement with the DUP in the short term, Mr Murphy said: "We have to ascertain who we are dealing with on the other side of the table.
"So we need to ascertain all of those things. That could open up into a period of nothing happening and I don't think that's good for any of us."
He said that since the talks collapsed, the DUP appeared to be "further away now perhaps than they were at the start of the last negotiation process" from being in a position to strike a deal.
Mr Murphy made the comments as his party formally lodged a submission with the Boundary Commission expressing concern about proposed changes to Northern Ireland's electoral map.
Sinn Féin claims the changes that have been made to a second draft of a blueprint to redraw the region's constituency boundaries directly favour the DUP, contending that at least four constituencies could be without any nationalist representation at Westminster or Assembly level.
Asked about a suggestion floated by Taoiseach Leo Varadkar earlier this week that the UK and Irish governments could jointly table their view of an equitable deal as a means to break the Stormont deadlock, Mr Murphy said Mr Varadkar needed to provide more detail.
He also expressed scepticism over Northern Ireland Secretary Karen Bradley's decision to examine alternate governance arrangements that fall half way between devolution and direct rule, such as giving MLAs some form of scrutiny role over decisions taken at Westminster.
"The ideas being floated by the Secretary of State don't seem to provide any momentum at all," he said.
He reiterated Sinn Féin's call for the two governments to intervene and jointly take action on disputes over the Irish language, same-sex marriage and the funding of legacy inquests.