The row over the stalled shake-up of councils in Northern Ireland has reignited as Stormont's Environment Minister aimed a broadside at Martin McGuinness.

Edwin Poots laid the blame for the hold-up in delivering the cost-cutting reorganisation of local government firmly at the door of the Deputy First Minister.

Sinn Fein responded by accusing the DUP minister of trying to shift focus from his own culpability in the review of public administration (RPA) logjam.

The proposal to reduce the number of councils from 26 to 11 hit the rocks in June when executive ministers failed to reach agreement ahead of the deadline to implement the changes for next year's local government elections.

A series of other measures to modernise and update governance and service delivery within councils and improve co-operation contained in the reorganisation Bill have also been held up as a result.

Mr Poots told the Assembly: "I should say that particular piece of legislation has been sitting with the Deputy First Minister's office now for well over a year and a half, coming up on two years," he said.

"That particular piece of legislation Mr Deputy Speaker does deal with minority rights (of political parties in councils) and ensuring that minorities are protected and I would ask this House to challenge the Deputy First Minister's office as to why it has held back this piece of legislation for almost two years and for the blocking mechanism that they put in place to the review of public administration advancing as fast as it should have."

Disagreement over boundaries and a debate on whether councils should shoulder the cost of the reform are among the sticking points around the review.

The rationalisation proposals, which were first set out two years ago, are estimated to save £400 million in 25 years.

A Sinn Fein spokesman said Mr Poots' claims were not accurate, saying: "Edwin has realised he's made a mistake over RPA and that he's going to have to face the electorate and justify why he didn't implement RPA and the £400 million savings it would have brought."