The Ulster Unionists have attempted to heap more pressure on the DUP by demanding a Maze-style U-turn over the shake-up of local councils.
With the dust still settling on Peter Robinson's dramatic about-turn by withdrawing support for the Maze peace centre, his main electoral rivals are now seeking to exploit DUP vulnerability over another key issue that divides them.
The UUP has long favoured a reduction of the present 26 councils to 15, rather than 11, as is planned. It argues 11 will create unworkable boundaries and hand over control of Belfast City Council to republicans.
But the DUP and Sinn Fein voted the 11 super councils system through the Executive, despite opposition from the sole UUP and SDLP ministers.
Former UUP leader Tom Elliott said the agreement on the shape of local government was "another sop to Sinn Fein".
"We have seen how people power has forced a massive U-turn from the First Minister and his party colleagues on the Maze terror shrine; perhaps it is also time for him to stand up to Sinn Fein on other major issues," Mr Elliott argued.
"It is not too late to pull the pin on these crazy proposals that see Dundonald become part of Lisburn, and Saintfield part of Newry. There is no rationale or logic; the costs involved far outweigh the saving in the short to medium term, and in all likelihood it is going to leave ratepayers millions of pounds out of pocket." Mr Elliott said he was glad the DUP "eventually saw sense" over the Maze proposal.
The DUP chose, instead, to maintain its focus on Sinn Fein.
Lagan Valley MLA Brenda Hale said: "To equate the sacrifice of those who fought in a legitimate army with the actions of criminals is simply sickening."
The spat raged on as a Scottish academic proposed an alternative location for the Maze peace centre at the Titanic Quarter.
Writing in today's Belfast Telegraph, William JV Neill, emeritus professor of urban planning at the University of Aberdeen, said: "If an iconic building is needed for a Conflict Transformation Centre, surely the former headquarters building of Harland and Wolff is an obvious choice."
First Minister Peter Robinson withdrew his backing from proposals to construct a peace and conflict resolution centre on the site of the former Maze prison. The DUP leader said there must be a change of attitude by Sinn Fein, especially towards victims of the IRA, following the recent Castlederg commemoration parade.
The peace centre forms part of a £300m redevelopment plan.