SO – TODAY’S THE DAY. With a series of cabinet meetings having been wrapped up and the minutiae of spending cuts pored over, today Michael Noonan and Brendan Howlin will publicly announce the €3.5 billion of spending cuts and tax increases of Budget 2013.

The Budget is probably the biggest day on the political and parliamentary calendar – with its impact felt right throughout the year at all levels of society, while the longer-than-usual hours will also see politicians debating and voting well into the night.

Today, however, really only marks the beginning of a process that could take up to six months to complete – because most of the Budget measures are too complicated to put in place so quickly.

There will be a series of votes on various measures tonight, between 7:30pm and midnight (the Dáil’s latest sitting of the year) – but in actual fact, very few of the Budget measures will be voted on by TDs today.

Most new measures announced today will be introduced in various Bills to be put to the Oireachtas in the coming months. The Finance Act, which tends to include most of the new tax measures, tends not to become law until April (though its actions are usually imposed retrospectively, to take effect from January 1).

There’s also the Social Welfare Act, which amends the systems under which various welfare payments are divvied out, and other pieces of legislation like the Appropriations Act which formally empowers the government to spend money from the ‘Central Fund’ where national income is stored.

(In fact, this last one is always a bit of a curiosity – even though it is the single piece of legislation which controls all government spending, its contents have been debated so much in advance that it passes the Dáil without as much as a whisper from TDs on any side of the house.)

The property tax, one of the few items we know is being introduced, will also be introduced in an Act of its own – in one that repeals the Household Charge Act passed by the Oireachtas last December.

Act now, but Acts later

So because most of the nitty-gritty will take months to deal with, today’s business will be about the speeches – the first one from Michael Noonan, indicating where the government intends to find an extra €2.25 billion, and the second one from Brendan Howlin outlining where spending will be cut by €1.25 billion.

After the traditional minister-holding-book-and-CD photo at 1:50pm, the speeches kick off at 2:30pm and will be done by about 4pm – at which time the government will publish the full documents outlining its financial plans, and revealing some of the nitty-gritty details which won’t have been included in the public speeches.

It’s then that the ‘financial resolutions’ – the matters being voted on tonight – will be published.

These are voted on tonight simply because their effects are due to kick in immediately. If the ‘old reliables’ of alcohol, cigarettes and petrol are hit in the Budget – as they are expected to be – then these proposals will be considered tonight.

There’s usually about a dozen of them, dealing with matters like carbon tax, motor tax and VAT – and these give the first indication of whether any government back-benchers intend to jump ship and vote against their own ministers’ measures.

These are the only measures which can kick in immediately – the finance ministers have relatively few powers that they can exercise without prior approval of the Dáil. The rest, irrespective of how controversial or simple they might be, will take some time to bring into effect.

Exchequer returns: Government’s tax take 0.5 per cent below target

Readers’ Panel: What are you expecting from Budget 2013? Parts one and two