The looming battle between unions and the Government over reductions in public spending took another turn this morning as trade unions voted in favour of the possibility of joint action to counter the cuts.

But yesterday, characterising the coming conflict as a ‘war’ between the Coalition and trade unions, News of the World columnist Fraser Nelson offered up information he said would serve as ammunition for George Osborne when he makes the case for cuts.

Mr Nelson stated: “For the public sector, there has been NO recession. Unpublished figures, seen by yours truly, show it has added 194,000 more jobs since the crash. Meanwhile, the rest of the economy has lost 884,000 jobs.”

To put the claim in context Full Fact took a look through the published figures.

Whichever way ‘since the crash’ is defined, there has been a significant rise in public sector employment during the recession.

If it is measured since the crisis of September 2008, then quarter on quarter there has been a rise of 287,000. But if measured since the start of the recession in the second quarter of 2008, then there has been a rise of 313,000 workers in the public sector.

But these rises - both far greater than the one quoted by Mr Nelson – make use of figures which include those most unlikely of public servants; bankers.

As the Government bought up the banks to save them from oblivion, staff from Northern Rock, then Bradford & Bingley, and finally the Royal Bank of Scotland and Lloyds were included in the public sector employment totals.

This means that, as the graph below shows, there was a huge leap in the headcount figures for the last quarter of 2008 when an additional 249,000 public sector workers were counted.

The explanatory notes in the Office for National Statistics (ONS) bulletin show the extent to which this was affected by the bank bail outs.

In the third quarter of 2008 there were 10,700 public sector workers employed in banking. By the end of the fourth quarter this number had hit 238,800.

However the figure has since fallen while overall public sector employment has continued to rise. At the end of the first quarter 2010, there were still 218,400 people working in financial corporations classed as public sector workers – a fall of around 20,000, while public sector employment as a whole was up 38,000.

This investigation is not trying to suggest the rise highlighted by Mr Nelson’s figures is solely accounted for by the advent of the public sector banker, but merely explores their role in the publically-available headcounts since the 2008 crash.

Indeed the level of private sector employment in the most recent ONS bulletin also differs from that given by Mr Nelson.

The problem is that the use of unpublished statistics leaves it very hard to put the quoted trend in context.

When we contacted the ONS about the figures they told us the latest bulletin on public sector employment is due out on Wednesday, so it will be worth examining the data again when new information becomes available.

Nevertheless, it is certainly true to say that public sector employment did continue to rise during the recession; it is simply a question of the extent and nature of that rise.

Full Fact has previously looked at the unpublished figures used by Mr Nelson in his column, and this latest case only further highlights the problem of auditing claims made on the strength of unpublished evidence.

Back in August we looked at such information cited in the News of the World about employment among UK and Eastern European workers and found that there was another side to the story when the full range of official figures were examined.

We are not trying to suggest that the figures used by Mr Nelson are wrong, merely that when they differ from the available official figures, they should be treated with a degree of caution, given the lack of public access to the dataset.

Full Fact will update on Wednesday assessing how the claim compares to the latest figures.