The government is seeking more changes to the last-minute Palmer United party (PUP) amendment that derailed the repeal of the carbon tax, as business warns it imposes unreasonable red tape and may apply to shopping centres, caravan parks, car dealers and shops selling fridges.

After the chaotic scenes in the Senate on Thursday morning, the leader of the government in the Senate, Eric Abetz, said the government had agreed to the 11th-hour PUP amendment and would back it in the House of Representatives next week, with the amended legislation then proceeding to the Senate so the tax could finally be repealed.



But Guardian Australia understands the government is now seeking further changes to clarify the intent of the amendments before the repeal is reconsidered on Monday.



The PUP is understood to be considering some changes and the repeal is still likely to pass next week, but continuing negotiations and the PUP’s unpredictability adds to the confusion and uncertainty surrounding the process.



The prime minister, Tony Abbott, told the party faithful at the LNP state conference in Brisbane on Saturday to say Thursday's vote wouldn't be a deterrent to his plans to scrap the tax. "We won't rest until the carbon tax is gone," he said.



Abbott refused to criticise Clive Palmer's involvement in last week's Senate vote, instead switching the focus to Labor's reluctance to rid Australia of the tax.

The government is now working to an extremely tight deadline to achieve the repeal it has effectively backdated to 1 July because electricity retailers have agreed to go along with the backdating only if the legislation is passed by 18 July – next Friday.



Business groups examining the final version of the PUP amendment are growing increasingly concerned, with manufacturers warning they could draw in anyone selling or servicing whitegoods such as fridges, air-conditioners, LPG cylinders or some mining equipment, and possibly businesses that on-sell electricity, such as shopping malls or caravan parks. Electricity retailers are also worried about the burden of the now compulsory regulatory requirements.



The government was deeply embarrassed and angered by Thursday’s Senate chaos and what many see as a last-minute ambush by Palmer.



But on Friday Tony Abbott insisted Senate negotiations with minor parties was “situation normal”.



“It’s perfectly normal for governments to have to negotiate elements of its budget through the Senate and it’s by no means unusual for some elements of the budget to be before the Senate six months, 12 months or even 18 months later,” the prime minister said.



“Obviously all governments have got to negotiate their legislation through the Senate. There’s hardly been a postwar government that hasn’t had to negotiate legislation through the Senate.”



And he suggested the chaos might have been caused by the PUP senators’ inexperience.



"This is the kind of thing that you could expect with a new Senate, with people coming in who don't have a lot of parliamentary experience," he said at a press conference in Sydney.



While the prime minister and his ministers are publicly restrained in their comments about PUP, PUP senators had no such inhibitions.



“We try to give them a little bit of trust and they’ve just blown it out of the water, so I guess it is just open slather,” said Tasmanian PUP senator Jacqui Lambie, alleging the government had tried to “trick” her party.



“If you want to come into the kennel with the PUPs be prepared to be chewed up and spat back out,” she told Channel 10.



The Australian Industry Group (AIG) is deeply concerned about the potential consequences of the amendment and the chaotic processes.



“AI Group is still taking stock of the proposed PUP amendments. But it appears they would impose a reporting requirement on a lot of businesses, not just big electricity and gas retailers. Caravan parks and shopping centres would have to report – they often buy electricity and sell it on to their tenants,” said chief executive Innes Willox.



“Anyone selling equipment that includes synthetic greenhouse gases would be covered. That appears to include car dealers and importers, wholesalers, retailers and aftermarket sellers of fridges, freezers and air conditioners,” Willox said.



“Equipment suppliers to mining and the electricity sector may also be caught up. We would assume that in working on the amendment the government would take industry concerns on board to make it far less onerous on the business community. We hope that there aren’t any further left-field amendments next week that could create unnecessary confusion and uncertainty and prevent the rapid repeal of the carbon tax.”



Electricity retailers were also concerned, said Cameron O’Reilly, chief executive of the Energy Retailers Association of Australia.



“Our key priority is to see the repeal legislation pass through both houses by the deadline of the end of next week but we hope the government ensures there aren’t unfair and unrealistic burdens placed on retailers in the process,” O’Reilly said.



The environment minister, Greg Hunt, told ABC radio on Friday he did not believe PUP intended the amendments to be so broad.



“The statement from Mr Palmer was his focus was electricity and gas supplies, but we will work constructively with Mr Palmer to ensure his concerns are met but we are on a deadline of the end of next week to ensure costs are reduced,” he said.



The opposition leader, Bill Shorten, attacked the government for being prepared to back the amendments on Thursday to save face, without having properly considered them.



“Does anyone seriously think the Abbott government gave this more than a cursory glance … they would have agreed to anything Clive Palmer asked yesterday,” Shorten said.

