It has been gathering momentum for some time now but as the election draws near, it has been reaching a crescendo - the war of words against farming, particularly dairy, regarding its impact on the environment and specifically water quality.
Much, especially where it is backed by sound scientific analysis, is justified but sadly the findings are increasingly being politicised so that those who make their living off the land, feed the rest of us and create wealth in the form of employment and export dollars are being vilified.
No one denies that much needs to be done but what is ignored is just how much has been, and still is being, done to ensure farming and the environment co-exist.
Central to any rational debate is the fact farmers do see themselves as stewards of the land and that, in order to make a living, they have to care for it and hand it on in at least better shape than when they took ownership of it.
Of course, some practices are unacceptable by today's standards and some huge and intensive farms will have to change or cease as they are. But the vitriol, false accusations and now the threat of taxes have gone too far.
"Swimmable rivers", "Clean up our waterways" may be political catchcries that appeal to urban dwellers - as though farmers were the only polluters on the planet - but the facts around efforts being made to address pollution issues get lost in the hysteria.
So, in defence of dairy farmers, let's look at some of what they are doing:
* In the last five years more than $1 billion invested in environmental issues.
* Advanced effluent management using smart technology.
* Stock exclusion; riparian planting; creation of strategic wetlands.
* Tens of thousands of kilometres of fencing excluding their cows from waterways.
But instead of acknowledging these massive $1b-plus efforts, there is a proposal to tax farmers.
While such a policy might appeal to the urban voter, it ignores three basic facts:
1). Every dollar siphoned off in tax is a dollar no longer available to the landowner to invest in his farm. You cannot have a healthy environment without the money to invest in keeping it healthy.
2). Politicians are dreaming if they think they can spend the money more effectively than the farmer whose very livelihood depends on a healthy farm.
3). Any new tax runs the risk of being the straw that breaks the camel's back.
I spoke to a Canterbury farmer last week who had just completed spending $100,000 ensuring his nitrate content in the soil was at an acceptable level and that all his stock was excluded from waterways.
Ranked in the top 1 per cent of the region's dairy farms, he was concerned that a water tax, or royalty, would spell the end of their time on that 450-cow farm.
Something that really riles dairy farmers are the posters showing beef cattle in a stream yet labelled "dirty dairying".
Separating fact from hype during an election campaign can be difficult but we have to remember that every item of food produced is dependent on water plus the skill and wellbeing of those whose sweat and dedication utilise it for the benefit of us all. And it is not free to the farmer - especially if he is dependent on irrigation.
In a Whanganui shop recently a woman who works as a counsellor for rural people under stress and mental fatigue was heard to comment that a proposed water tax would impact severely on many farming families.
A woman bystander joined in with: "And they jolly well deserve it - we've been subsidising them for far too long."
Really? Has our society come to this where our hardworking fellow citizens are to be maligned by others assuming a victim role as the result of cheap vote-catching politics? Perhaps it's time to tell some people: "Don't criticise farmers with your mouth full."
* Allan Anderson was a farmer in the Waitotara Valley for 42 years, is a longstanding member of Forest & Bird and is a dedicated conservationist, receiving the Queen's Service Medal for services to conservation and the community in 2009.