Federal Treasurer Joe Hockey says it would be "regrettable" if businesses restructure their paid parental leave schemes to ensure workers still qualified for Commonwealth payments, describing such a move as a "scam".

This week's budget included plans to save about $1 billion over four years by stopping new parents claiming paid leave from both their employer and the Federal Government.

Business groups warned some employers might scrap their own schemes in response to the change or restructure payments to allow their employees to continue claiming leave from the Commonwealth.

Mr Hockey said such a move would be regrettable.

"It's something we will have a look at, but a good employer will offer fair-dinkum paid parental leave to their employees, like the ABC does, like the Government does, like many businesses do," he said.

"If they change the scheme to try and scam the Government and scam taxpayers ... that reflects on them as much as anything else.

"What they're trying to do is utilise what is meant to be a safety net and changing their own scheme for their employees, which should be at replacement wages."

Support for Government's plan split in Senate

Some ministers have described the so-called double dipping as unfair and a "rort", even though both the Assistant Treasurer Josh Frydenberg and Finance Minister Mathias Cormann have admitted their wives took advantage of two schemes following the births of their children.

Labor and the Greens are opposed to the change and at this stage it is unclear whether the Government has enough support to get the savings measure through the Senate.

So far Liberal Democratic Party senator David Leyonhjelm and Family First senator Bob Day are the only crossbenchers who have publicly supported the plan, while independent senator Jacqui Lambie and Palmer United's Dio Wang have both said they would vote against it.

Independent senators Nick Xenophon and John Madigan said they were still considering their positions while Motoring Enthusiast Party senator Ricky Muir said he would be seeking a briefing from the Social Services Department before making up his mind.

"Senator Muir is concerned about impact that it may have on lower-paid workers and any unintended consequences that may arise if it is implemented, including the fact it might mean that employers end up saving money, not the Government," his office said in a statement.