This article has been updated
Mayor of London Boris Johnson found himself under fire at the tail end of last week after he claimed that the number of police officers on London's streets would rise by over 1,000 by 2015.
His Labour opponents in the Greater London Assembly, by contrast, have argued that the total rise is a much more modest 56, and has accused Mr Johnson of using "dodgy stats". They have also asked the UK Statistics Authority to intervene on the issue.
So what is all the fuss about?
The controversy stems from the proposals outlined earlier this year in the Mayor's Draft Police and Crime Plan, which is currently out for consultation.
In it, the Mayor claims that the total number of officers available across all the London boroughs will rise from a baseline of 18,103 in October 2011 (a date picked because "it marks the beginning of the programme to redesign local policing services") to 19,285 in 2015, an increase of nearly 1,200.
However Labour claims that there were actually more officers available in October 2011 than this would suggest, and points to the Mayor's own policing data, which records that there were 19,229 officers available in October 2011. If this were to increase to the 19,285 that the Mayor is aiming for, the rise would be just 56.
Furthermore, these statistics show that police officers in London have actually declined since, with 18,286 reporting for duty in December 2012.
This isn't necessarily incompatible with the figures set out in the Mayor's plan, which notes that "officers will be brought in to fill the additional posts throughout 2013-15," however it does suggest that there hasn't been a uniform improvement over the period.
So why are the two sets of figures so different?
The source of the confusion seems to be that the two sets of figures refer to different things. While the Mayor's office has told the BBC that the Crime Plan uses "the budgeted figures for 2011" (i.e. the number of officers the Met had planned to have when it budgeted for that year), the figures on the Mayor's website are the number of Full Time Equivalent (FTE) officers recorded at the time.
This means that there were the equivalent of 19,229 full time officer posts in the Met in October 2011, not the budgeted 18,103, although some of these might have been staffed by police men and women working part-time.
Given that the Crime Plan was published in January of this year, it might seem strange to use forecasts for officer numbers from previous budgets as the baseline when actual numbers are available, although the Mayor's office claim that this is the "relevant comparison". Whether or not the UK Statistics Authority agrees remains to be seen.
Update (22 March 2013)
The Chair of the UK Statistics Authority, Andrew Dilnot, this week wrote back to Labour's Joanne McCartney AM who initially highlighted the discrepancy, and to the Mayor Boris Johnson.
He agreed that the figures from the Mayor's Draft Police and Crime Plan and the online Metropolitan police strength data were different in spite of ostensibly measuring the same thing, and also highlighted that Home Office National Statistics presented different figures to both for the same end of month snapshots.
Why the difference? Mr Dilnot cited a number of explanations, including differences in how the datasets count staff on maternity leave, secondment to and from other forces and career breaks.
As a result, Mr Dilnot wrote to the Mayor asking him to arrange for a new set of figures to 'reconcile' the three different sets of figures on police strength. This would, in the words of the watchdog's Chair:
"assist informed public debate on this important matter and avoid any confusion that may have inadvertently been generated about the true picture in respect of policing numbers in London."
Full Fact couldn't agree more, and we look forward to seeing clearer figures on police strength from the Mayor in due course, in addition to a clear and formal commitment from the Greater London Authority to sign up to the Code of Practice for official statistics.