When Minister for Finance Michael Noonan stands up in less than a month to deliver Budget 2017, he and his mandarins might want to think carefully about diesel tax.

One stroke of a pen could add on €600 to the average farmer’s annual fuel bill. As we reported last week, one of the many kites being flown before the budget on 11 October is the proposal to bring the taxation for diesel in line with that of petrol.

Should this occur, the price of white diesel could increase by as much as 12c/litre.

I read this and so I got my envelope and started doing the maths on the taxes.

I took a standard farmer who uses the 4x4 for daily farm use. He or she could be facing a cost increase of close to €600 per year in additional fuel costs if the two fuels were to be equalled in price. I looked at the ever-popular Toyota Land Cruiser and found that additional annual fuel running cost would be €597 over a year based on an annual use level of 50,000km, if the prices were to be increased by additional taxation. This would equate to a consumption figure of close to a 90 litre tank fill almost every week of the year.

That’s not a jeep hauling weight or a trailer either. That’s just your standard vehicle going to and from the mart, the shop, the school, and so on.

I also had a natter with the people who use a lot of diesel, the farm contractors. Their best estimates suggest that bringing the diesel and petrol tax closer together could add €2,000 to the annual fuel bill because many contractors run a 4x4 as well as a van or two.

So my message to the minister is simple – think before you jump on the diesel tax issue.