There are concerns from the farming industry over the potential impact of a capital gains tax.

Farms are currently not subject to a capital gains tax (CGT) when they sell. However, if someone buys a property that is not their home they are taxed on its sale if they keep it less than five years.

Farmers pay GST on all purchases and company tax of 28 per cent. If they use a trust structure, any profit is subject to 33 per cent tax.

NZ Herald Business editor Duncan Bridgeman told Kate Hawkesby the majority of farmers have kept relatively quiet about this issue, but underneath they are seething. 

"The farming industry is probably the hardest industry to be hit. As you mentioned the environmental taxes and capital gains on the property is a real concern."

Bridgeman says there is a lot of rhetoric out in the public that farmers are not paying their fair share of tax.

"That may be correct in certain instances. For example, a dairy farm that might turnover $5 million a year but is paying $6 million in costs is actually making a loss. You don't get taxed on your profits so people look and see them turning over millions and a high dairy payout and think they should be taxed more.

"But when you put that against a person who owns a couple of villas in Auckland and doesn't work for their money at all, it really doesn't stack up."

The farm's family home would be exempt but any home site area over 4500sqm would be subject to a CGT. Increases in livestock herd value would be subject to tax.