Martin McGuinness was speaking at the Sinn Fein party conference in Dublin
Martin McGuinness has told the Sinn Fein party conference the UUP have "three days to sort themselves out" over the issue of policing and justice.
UUP leader Sir Reg Empey has said his party is not yet in a position to back the transfer of powers.
The Deputy First Minister accused the UUP of pursuing a "negative and rejectionist agenda" on the matter.
Education Minister Caitriona Ruane told delegates at the RDS in Dublin there was no going back to the old 11 plus.
Sir Reg Empey has said that his party will not sign up to a deal on policing unless other issues currently under the control of the executive, such as
can be solved.
Mr McGuinness said the Ulster Unionist Party were out of step with majority unionist thinking.
"So is Reg Empey really saying that he is threatening the political institutions because Caitriona Ruane won't re-introduce the 11 plus?," he said
"What is more dysfunctional than that I ask?"
Ms Ruane said she was proud that Sinn Fein had got rid of academic selection which she said was "really academic rejection for the majority of young pupils".
"The 11 plus was morally wrong, educationally unsound and it inflicted year on year wholly unnecessary trauma and suffering on 10 and 11-year-old children," she said.
"I want to give an absolute assurance that it will not be replaced by any other such high-stake tests as part of our transfer procedures."
Sinn Fein President Gerry Adams is to address the annual conference later on Saturday.
He is expected to focus on the Irish Republic's economic and political woes.
Mr Adams is also expected to call for cross-party support for a vote on the devolution of policing powers to Northern Ireland.
Debate at conference on Friday centred on whether the party should enter any coalition with Fine Gael or Fianna Fail after the next general election.
Sinn Fein operates on an all-Ireland basis but its electoral success in Northern Ireland has not been mirrored in the Republic of Ireland.
Last July, County Kerry-based Sinn Fein councillor Toireasa Ferris said the party "means nothing" to the bulk of voters in the Republic, who saw Sinn Fein as a northern-based party.
Her comments followed a disappointing performance in elections which saw Sinn Fein vice-president Mary-Lou McDonald lose her seat in the European parliament.
The conference comes days ahead of a cross-community vote in the Northern Ireland Assembly on whether to accept the devolution of policing and justice powers from Westminster to Stormont.
NI Secretary of State Shaun Woodward said Tuesday's vote would be "nothing less than a vote for the future of Northern Ireland".
The DUP and Sinn Fein have enough Assembly members to ensure the passage of the vote on the deal reached at Hillsborough last month.
Citing the Northern Ireland Executive's "dysfunctionality", Sir Reg Empey said on Friday it "must be capable of exercising its existing powers before such an important issue as policing and justice is devolved".
Mr McGuinness accused Sir Reg of showing "a dismal failure of leadership".
The Sinn Fein Ard Fheis was streamed live on the BBC news website from 1130 GMT on Saturday. Coverage will resume with Gerry Adams's speech at 2015 GMT.