Stand by dairy farmers, Labor tells Joyce

Labor doesn't think Agriculture Minister Barnaby Joyce is doing enough to support farmers angry at a decision by two dairy giants to slash farm gate prices.

"His silence has been deafening," opposition agriculture spokesman Joel Fitzgibbon told AAP on Sunday, of Mr Joyce's decision to wait until Monday to contact Fonterra and Murray-Goulburn.

"This thing is almost three weeks old and he's not said a word."

Both processors have reduced the price they pay farmers for milk solids from $5.60 a kilogram to between $4.75 and $5 a kilogram in the past month.

The Australian Competition and Consumer Commission will examine the timing and notice of the cuts.

"The ACCC will consider whether the changes have involved misleading conduct or whether there are elements of unconscionable conduct," chairman Rod Sims said.

Processors blame a slump in global prices - about 60 per cent since early 2014 - for their decision.

Mr Fitzgibbon says Mr Joyce needs to do more than just make a telephone call to executives.

"He needs to stand by farmers and show them he has their support."

Because processors are implementing the cuts retrospectively, farmers claim they are effectively getting paid less than $2 a kilo.