Minister for Finance Michael Noonan has been challenged to publish data proving his claim that the budget can take less than €2 billion from the economy.

Labour backbencher Kevin Humphreys is calling on Mr Noonan to explain his calculations which defy advice from the International Monetary Fund (IMF) and the European Commission (EC).

The Government-appointed Irish Fiscal Advisory Committee (Ifac) has also insisted the Coalition should maintain the target of €2 billion in cuts and new taxes.

“If Minister Noonan has information and projections to show we are on target to overshoot our deficit target for 2014 by €2 billion we need to see that information,” Mr Humphreys said.

“If there is data to show that our economic situation has improved and that budgetary targets will be met with a no change scenario that information needs to be in the public domain.”

Mr Noonan this week told an Oireachtas committee that economic conditions had improved since April, when the Department of Finance set a €2 billion retrenchment package would be required to reach the EU-mandated target next year of a budget deficit below three per cent of economic output.

Mr Noonan said he was now fairly confident less than €2 billion would be required to get the deficit below three per cent.

However, Mr Humphreys cautioned against “reckless” speculation over the summer months.

“We cannot allow electioneering, reckless promises and speculation to put our economic salvation at risk,” he said.

“Clarity is urgently needed to put conjecture to bed, and cold hard facts on the table,” he said.

Mr Humphreys said he believed Mr Noonan’s projections were based on Exchequer returns for the first five months of the year, along with indicators such as car sales and industrial indices.

“Soft data” and internal projections from within the Department of Finance were also being factored in, he said.

However, he said “loose talk about the Budget, without any hard figures to back it up” was not helpful.

Separately, he said commentators should not make “damaging assumptions” about how long the Government will last. Mr Humpheys said he believed the Coalition would remain in place until 2016, as originally planned.