FAILURE to impose the British government's latest round of welfare cuts could end up costing Stormont more than £100m a year - on top of multi-million pound penalties already being paid.
The north's main parties are currently locked in talks to resolve a crisis over welfare reform and continued paramilitary activity.
But with Sinn Fein and the DUP already at odds over benefit changes announced in 2012, politicians have the added task of reaching agreement on fresh cuts in Chancellor George Osborne's July budget.
Figures released by the Department of Social Development now show the scale of the latest welfare cutbacks.
The July cuts will take more than £200m from the north's welfare bill in the next financial year, and Stormont will have to cover some of that saving if they are not implemented.
Most of the latest reforms, including changes to tax credits, will be introduced automatically next year because they are "reserved matters" and can be imposed without the assembly's approval.
It is estimated more than 120,000 households in the north will lose an average of £900 a year from cuts to tax credits.
But some of the key changes, including a further reduction in the benefits cap, are devolved matters and will required agreement at the assembly.
The figures show failure to implement a £20,000 benefits cap will cost the Executive £7m a year alone.
In addition, the penalties will dramatically increase if Stormont does not agree to the introduction of universal credit - a measure aimed at simplifying the benefits system - meaning that essential services including health and education, which are already under severe pressure, are likely to be hit by further cuts.
