The government is split on Tony Abbott’s signature paid parental leave (PPL) scheme, as three National senators committed to vote against the scheme, while Joe Hockey issued a strong warning to senators planning on blocking parts of the budget.



“I would say to the naysayers about the Senate, if the Senate is simply saying no to everything we do, it becomes irrelevant,” the treasurer said in answer to a question on the Medicare co-payment.



“In one sense, it is hugely relevant in that it is disrupting the role of government, but if it just continually says no without any capacity to negotiate an improved outcome then the Senate becomes irrelevant.



“It's just simply a road block and we either have to smash through that road block or the Australian people get the chance to change the government.”



Hockey’s comments were aimed not only at crossbenchers but at the National party senators Ron Boswell, John Williams and Barry O’Sullivan who have confirmed they will vote against PPL.



Of the National party’s six senators (including Country Liberal Party senator Nigel Scullion) only Bridget McKenzie and Fiona Nash have confirmed they support the scheme. Scullion has yet to confirm how he will vote.



Boswell argued PPL was unfair to rural Australians, who generally earn less than their city counterparts, and would discriminate against stay-at-home mothers.



“You help the weak, not the strong,’’ Boswell told the Australian.



But on Monday Hockey appealed directly to the National party and its constituency, urging it to focus on the beneficiaries.



“If people focus on the beneficiaries, they will soon understand that the biggest winners are people in regional Australia, particularly farmers, and lower income people and also small business,” Hockey said.



“A lot of the mums in a farming household, they don’t get paid parental leave and now they are going to get replacement wages plus superannuation.



“It is a no-brainer for regional Australia and it’s a no-brainer for middle and lower income Australia at full replacement wages, particularly when the bills come in.”



Last week a senior Liberal source boasted to the ABC that the Nationals were “played” by the Liberals into accepting the fuel excise changes in the budget by leaking reports that the diesel fuel rebate would be cut. The fuel excise was seen as the most palatable option for the Nationals’ rural constituency.



The National party is under pressure from Clive Palmer’s support in rural Australia. The latest Essential polling has the National party picking up 3% of first preferences, with the Palmer United party on 6%. Weekend polling put the PUP on 13% in Queensland.



Boswell said Palmer should not be allowed to take credit for stopping PPL, which a number of National party members have long opposed in the government joint party room.



Boswell confirmed he would vote against the prime minister’s signature policy, which pays mothers six months’ wages on salaries up to $100,000, allowing them to receive a maximum of $50,000.



Asked about PUP’s polling at the weekend, the acting prime minister and leader of the National party, Warren Truss, acknowledged there was a strong protest vote in regional Australia.



“There are always people who are unwilling to support the major parties. That's especially true in regional Australia, in electorates like mine. Palmer, Katter, other independents always poll 15 or 20% of the vote.



“So there are people who prefer to place their votes somewhere else. Often it's a protest vote against the major parties.”

Originally, the government hoped to get the legislation through with the support of the Greens, albeit with a lower salary cap. But the Greens leader, Christine Milne, said she would reserve her judgment until the government released the bill.

Labor’s Alannah MacTiernan said the prime minister had “staked his leadership” on delivering the PPL scheme.

