The Ulster Unionist Party has reacted angrily to Arlene Foster's criticism of regional development minister Danny Kennedy's spending record.
The DUP finance minister took a swipe at her executive colleague after Mr Kennedy's department went over budget by £11.7m last year.
In a written update on Stormont's finances, Mrs Foster said it was "extremely disappointing" that the regional development minister was unable to live within his allocation "despite having been aware of the pressures facing his budget for some time".
She said Mr Kennedy's expectation of money to cover his spending plans "did not materialise due to the constraints".
"Overspending against an executive agreed allocation is an extremely serious matter that puts in jeopardy the executive’s ability to manage its budget effectively and live within its HM Treasury control totals," she said.
Mrs Foster said such a breach would normally warrant an equivalent reduction in the Department of Regional Development's current budget but the significant pressures the department was facing meant she would waive the penalty.
But Ulster Unionist MLA Adrian Cochrane-Watson accused the finance minister of "playing party politics".
He said the "technical overspend" by Mr Kennedy was the result of £40m being lost from his departmental budget in the last two years.
It is understood the money was originally deducted from DRD's four-year budget in 2011 by then finance minister Sammy Wilson.
At the time it was hoped the shortfall could be met by raiding Belfast's Port's reserves, but this was not permitted under the current legislation.
"If anything DRD made greater savings than any other department in 2014/15 with £8m in savings over and above the 4.4 per cent imposed in year across a number of departments," Mr Cochrane-Watson said.
"We are now at the end of the third week in July and Arlene Foster still hasn’t sorted out June monitoring – at the same time she is returning nearly 300K per day to Westminster for failing to resolve welfare reform.
"Her time would be better spent dealing with the real issues affecting Northern Ireland rather than playing party politics."
