On current forecasts, public spending will take the same proportion of national income in 2017–18 as it did in 2003–04. But it will be being spent on quite different things.

The OBR's second fiscal sustainability report, published today, reminds us of the significant challenges which we face as a result of the spending pressures created by population ageing and a likely loss of tax revenues from motoring and north sea oil and gas companies. We need to respond to this analysis by planning now for the changes to spending and taxes that will be required.

Official figures published today show, for the first time, estimated spending outturns by Whitehall departments for 2011-12. Despite most seeing their budgets cut between 2010-11 and 2011-12, Whitehall departments have underspent their allocations by an estimated £5.3 billion. In this observation we set out which departments did not spend their allocations.

Figures released today show that corporate tax receipts fell by 6.9% in October this year, compared to the same month last year. This observation highlights the recent trends in corporate tax revenues and discusses what is known about companies' tax payments.

Yesterday the International Monetary Fund published its latest Fiscal Monitor, which surveys public finance developments across the world and updates their fiscal projections. Here we look at some of the main fiscal projections and take stock of how the planned fiscal consolidation in the UK compares to those currently planned in other advanced economies.

The Office for Budget Responsibility's first 'Fiscal Sustainability Report' - published today - sets out some of the long-term challenges facing the UK's public finances. Demographic pressures alone could raise spending by £80 billion in today's terms by 2060, with a particularly striking increase required in health spending. Tax revenues, especially from oil and petrol, are also under pressure. Long term fiscal sustainability will require hard choices even after the unprecedented fiscal retrenchment planned for the next few years.

The Spending Review, to be finalised later this month, will provide detail regarding the large reductions in spending on public services that will be implemented over the next four years. The estimation of the distributional impacts of cuts in spending on public services is substantially more challenging than the estimation of the distributional impact of changes to taxation and the payment of cash benefits. For many reasons analyses of the former should be interpreted very cautiously.

The new coalition Government has announced a £6.2 billion headline cut to public spending in the current year. Since £500 million is being recycled into additional spending or tax cuts, and the £704 million earmarked for devolved administrations does not have to be found until next year, the likely reduction in borrowing in 2010-11 is around £5 billion. This is less than a tenth of the fiscal repair job that Alistair Darling's March 2010 Budget forecast suggested will be needed over the next few years.

Today's GDP figures show that the economy grew by 0.2% in the first quarter of 2010. In the election campaign much has been made of the impact of the timing of spending cuts and tax increases on the ability of the UK economy to sustain this recovery. This is an important issue, but much less attention has been given to the equally important question of how UK growth is likely to fare in the medium term which will be largely determined by efficiency with which we produce goods and services and the extent to which we develop new ideas.

The Liberal Democrats propose to increase the income tax personal allowance to £10,000 while keeping the level of income at which people start to pay the higher rate of tax unchanged. They say this giveaway would cost £16.8 billion in 2011-12. They also propose a set of significant tax-raising measures, but do their plans add up?

The Liberal Democrat manifesto contains more extensive and more detailed tax and spending proposals than those of the other main UK parties. But taking as given the Liberal Democrats' estimates of the amounts that their proposals will cost and raise, the document is less clear than it could be in setting out how these proposals fit into the party's overall plan to repair the public finances.

Last week Chancellor Alistair Darling warned us not to expect a giveaway in next week's Budget, while his Chief Secretary to the Treasury, Liam Byrne, reassured us that the Government could halve the deficit by 2013-14 without announcing any further tax increases. If both statements prove correct - no pre-election tax giveaway and no new post-election tax takeaway - then this would break the pattern of the last four general elections.

"Whoever wins the election, Labour or Conservative, is going to have to cut spending. That is not something that Margaret Thatcher actually did. So tougher than Margaret Thatcher." So said George Osborne on the Today Programme this morning - and the numbers by and large bear him out.

The Treasury's plans for public spending would require spending by central government on public services to be cut in real terms by 8.6% in 2013-14 compared to 2010-11. Is this too much or too little, and how should the pain be shared? A new tool, DIY Spending Review, that can be downloaded as an Excel spreadsheet enables you to carry your own "Spending Review 2010".

There is a lot we do not yet know about how Labour and the Conservatives would go about repairing Britain's battered public finances over the next few years. But yesterday's speeches by David Cameron and Alistair Darling at least highlight a sharp difference of opinion over what should be done next year. Yet the picture is quite not as straightforward as either makes out.

In Prime Minister's Questions this week Gordon Brown and David Cameron clashed over the Government's plans for spending on investment in public services. So how do the plans for investment spending going forwards compare to Labour's record to date and to that of previous Conservative Governments?

The International Monetary Fund has released the conclusions of its annual "Article IV" health-check for the UK economy. It endorses the Government's short-term fiscal giveaway to help ameliorate the recession (which the Conservatives say was a mistake), but says that it should be more ambitious in its plans to repair the public finances once the economic recovery is underway.

If the picture painted by the Treasury in this year’s Budget is correct, we are currently suffering a “bust” without having enjoyed a “boom”. But there is an alternative view of recent history that casts a less favourable light on Gordon Brown's tenure as Chancellor of the Exchequer.

Alistair Darling admitted yesterday that the underlying health of the public finances is much weaker than he thought in last year's Pre-Budget Report, and that it will take two full parliaments of intensifying austerity to get government borrowing back to acceptable levels.