INDEPENDENT Senator Jacqui Lambie has unleashed a finger pointing rant at the head of the National Farmer's Federation Fiona Simson. 

The dispute came about after Lambie put forward amendments to the Turnbull Government's backpacker tax which saw it pass the Senate at a lower rate than the Coalition had planned. 

Later outside in the Parliamentary gardens Lambie called Ms Simson out for the Federation's support of the tax - saying she was a lap-dog for the government and not supporting farmers. 

"They're (farmers) are already disadvantaged because of the lack of backbone that the National Farmers Federation have had in the first place," Lambie said. 

The Senator then said the NFF should have "stood it's ground" and back her proposal to keep the backpacker tax at a low 10.5% - instead of the 19% the Federal Government is asking for. 

Earlier today Senator Lambie's amended version of the controversial tax passed through the Senate today in a tight 30-37 vote with the Turnbull Government failing to block its passage. 

News Corp reports Lambie's new tax will come in at a rate of 10.5% - a big step down from the 19 per cent rate PM Malcolm Turnbull said he would be insisting on. 

"This is a plain act of economic vandalism by the Labor Party," Mr Turnbull told AAP after ALP supported Lambie's changes.  

"A plain act of undermining Australian businesses, Australian horticultural businesses, Australian tourism businesses."

The ABC reports the Coalition as saying this morning that the tax would be brought in at a rate of 32.5%, if its 19% proposal did not pass the Senate. 

Parliament will only sit for one more week this year and Lambie's new 10.5% backpacker tax will be sent back down to the House of Representatives, where the Coalition has the numbers. 

The tax can not be made law unless both the Senate and the House of Representatives agree on it.