We're currently running a deficit, which means that we're borrowing money to meet our spending commitments because national income (tax revenue, VAT, whatever) is lower than our national expenditure.
That is why we have to make cuts, otherwise we're borrowing more and more money in the hope that one day national income will rise significantly. There is no indication that this will happen in the near future and therefore it makes no sense to try and spend our way out of recession (which has worked in the past) and into growth.
We are paying interest on the debt, by the way, to the tune of 27.2 billion last year and 42.9 billion this year. If that's how much it rises in just one year, what do you think it would be after 10 years of making small meaningless cuts?
That's the thing. Debt is fine. Debt enables growth and investment. BUT only when you're running a surplus, when you have extra money to cover the repayments and interest. Otherwise you end up in the mess we're in.
We can see the problem with this way of thinking if we, as our wonderful chancellor lectured, look across the Irish sea. Ireland has cut public spending back massively to eliminate its deficit, the net result is that the Irish economy is finished, their credit rating gets downgraded, they can't pay back their debts and it's only a matter of time now before the IMF is called in.
The reason why we need national deficits is precisely to revive demand when private consumption implodes, which is what happened when the banking-led recession happened. Yes that means you have to reduce the deficit when private consumption recovers, but you sure as hell don't throw the baby out with the bathwater. I'm frankly astounded that the government remain keen on following Ireland into an IMF bailout.