Peter Robinson and Martin McGuinness clash over Stormont
The DUP and Sinn Féin have clashed over whether Northern Ireland's political institutions are fit for purpose.
Writing in the Belfast Telegraph, external, First Minister Peter Robinson had said arrangements for devolved government were "no longer fit for purpose".
However, Deputy First Minister Martin McGuinness questioned the motives of the DUP.
BBC News NI Political Editor Mark Devenport reports.