Figures released by the Treasury outlining the government’s spending and revenue collections for December underscore the uphill climb the state faces to meet its budget targets, as the economy sputters and government spending continues apace.

Revenue collections, particularly company income tax and VAT, were slower during December, a month that typically sees a spike in corporate tax collections, according to economists. At the same time, spending by the state into December was up more than 14% year on year...