On the middle Wednesday of every month, the Office for National Statistics (ONS) publishes the latest labour- market statistics for Scotland and, as inevitably as night follows day, the political bunfight which follows revolves almost exclusively around headline employment and unemployment statistics.

Deeper trends are largely ignored and this should frustrate anyone interested in how the changing Scottish labour market is affecting real people. ­Unemployment stagnating at a high level is bad enough but the enduring legacy of the last five years of depression is likely to be widespread economic insecurity.

Rising insecurity is reflected in the rapidly increasing use of zero-hours contracts. Only this week, the ONS revised upwards its estimate of the number of zero-hours contracts in the UK to 250,000, a doubling on the decade and an astonishing rise of one-third in the last year alone.

Yet there is near-consensus among labour market researchers that even this revision is a significant underestimate. It has recently been revealed that just two firms - SportsDirect and Wetherspoons - together employ 44,000 staff on zero-hours.

The care sector alone might account for north of 150,000 zero-hours jobs across the UK.

No accurate official figure is ­available for the number of zero-hours jobs in Scotland but apart from their growing prevalence in the English NHS due to new commissioning practices, the trends appear similar across the UK.

Zero hours are increasingly common in hospitality, retail, distribution, higher education and arts and leisure. Predictably, given pressure to cut costs, zero-hours are now being introduced into a range of public and voluntary sector workplaces.

It's important to pause and acknowledge that zero-hours contracts suit some workers, particularly those - mainly but not exclusively older workers - who can plan their finances and reconcile family commitments without the certainty of regular hours. It's also self-evident that these contracts work, in the short-term at least, for many employers.

But for most workers on zero-hours contracts the reality is grim. They are likely to get lower pay, work fewer hours, experience problems managing household expenditure, and be at higher risk of stress-induced mental illness. Their employment rights are undermined with the increase in zero hours. Access to tax credits becomes significantly more complex as the minimum hours of work required to qualify is increased.

Perhaps less well-recognised are the effects on service users and the wider economy. If essential care services are to be delivered by underpaid, insecure and stressed workers, then the quality of care will inevitably deteriorate. If the labour market is to have a ­growing share of insecure, low-wage jobs, the concomitant fall in demand diminishes the prospects for long-term macroeconomic stability.

What can Government do? An outright ban is probably premature, although the option should certainly not be dismissed. It is encouraging that Vince Cable has launched a review but its scope is too narrow and, given its wider approach to employment regulation, it's a brave soul who harbours any confidence in the Coalition to limit seriously employers' ability to run with these contracts.

Better information on the scale of use of zero-hours contracts and the ways they're being used to circumvent employment regulation is essential. There is no reason why the Scottish Government can't support research to this effect. Government at all levels also needs to examine the nature of jobs created before subsidies and grants are chucked at firms whose business models rely on exploitative practices.

The Scottish Government must directly address the growing prevalence of zero-hours contracts in the public services.

The Procurement Bill starting to wind its way through Parliamentary process would be a good place to start. Simply put, any firm exploiting workers on zero-hours contracts should be barred from receiving public contracts.

Zero-hours contracts are the UK labour market in microcosm: flexibility for employers, insecurity and falling wages for workers. Let no politician cite concern for rising inequality, low pay or job insecurity while remaining silent on the issue.