Minister Finian McGrath says spending on public services can't be cut to pay for wage demands.
He was speaking ahead of this morning's cabinet meeting, at which Ministers were briefed on the situation regarding public sector pay.
Thursday is the deadline given by SIPTU – who say they'll ballot 60,000 workers for industrial action if the government doesn't open new public pay talks.
A 40 million euro deal with the Gardaí has already been negotiated – and if an agreement is reached with teachers at the WRC it could add millions more to the government's pay spend.
Ministers were quick to defend their own departmental budgets though – with Finian McGrath saying he wouldn't take a cut.
Economist Colm McCarthy has suggested that to find the money the government may need to borrow on the international markets.
Details on public sector pay were brought to cabinet by Minister Paschal Donohoe this morning.