How much, in this age of austerity, should NHS staff or contractors be paid? Using the number of comments on HSJ’s website as a guide, no subject is of greater interest or importance.

The perceived or actual inequities of who is paid what - obscured during the years of plenty - are now leaping to the fore as the money gets tighter.

Agenda for Change is the proudest achievement of the NHS unions - they will defend its integrity tooth and nail

This week, HSJ’s readers have flocked to our site to express their views about GP pay and Panorama’s analysis of public sector staff paid more than £100,000. Anger - whether over value for money or inappropriate comparisons - was the abiding emotion.

But these debates are as gentle as spring breezes compared with the Hurricane Katrina of controversy brewing up over the freezing of agenda for change increments by foundation trusts, which could affect up to half a million NHS staff.

Agenda for change increments are different from uncertain cost of living rises (already frozen, of course). Increments are taken for granted by many staff, who make medium and long term financial decisions based on projected rises. The negotiation of Agenda for Change is the proudest achievement of the NHS unions - they will defend its integrity tooth and nail.

Given the stresses already built into the NHS by proposed reforms and financial pressures, is this a nettle that needs grasping?

Jim Easton, who leads the Department of Health’s QIPP efficiency drive, is already on the record as saying the NHS faces a choice between freezing increments and losing tens of thousands of jobs - but he is far from alone in that view.

Put simply, the leadership of the NHS believes achieving the much discussed £15bn saving target is impossible without reducing growth in the pay bill. Service change will deliver long term efficiencies but only constraining pay will make a difference quickly. Speed is important, they claim, because “falling behind” only increases the scale of savings needed in later years.

To have a significant effect the increment freeze needs to last at least two - and probably four - years. A one year freeze will neither deliver the necessary savings or allow trusts to plan ahead accurately.

Of course, Agenda for Change increments are a contractual obligation for existing staff, which is why most trusts are looking to begin with new recruits. However, in the near future they are likely to brave legal challenges to change the rights of current staff members.

But legal challenges will be just one barrier to delivering savings. Trusts will be understandably nervous of acting alone, particularly in the major cities, where staff can flee to other NHS employers. Then there is the problem of what happens if - as seems a real possibility - the government decides not to require NHS trusts to follow the lead of foundations. Reducing the total size of the pay bill at the required rate will be key.

It is understandable that organisations such as Norfolk and Norwich University Hospitals Foundation Trust are looking to review conditions when staff change jobs, but this could prove to be a drag on service reform.

What is needed most of all is an honest debate with staff about the financial challenges ahead and the range of possible solutions. For example, it might be possible for job and pay levels to be maintained in some areas if staff are prepared to work flexibly and, crucially, not expect a premium for doing so.

Unemployment during the recession did not reach expected levels, partly because companies tried hard to retain staff, who accepted changes to terms and conditions in return. The comparisons between the public and private sector approaches to workforce management are often shallow and inappropriate, but in this case there may be lessons to be learnt.

The hurricane of protest over NHS pay can be calmed by honest debate