Labor has pounced on revelations a Liberal-National Senate candidate floated cutting company tax to 12 per cent and questioned the point of child care.

Labor has launched an attack on a Liberal-National Senate candidate who suggested subsidising child care for three year olds was a conspiracy to boost government control of child-raising.

Gerard Rennick, who is in the winnable third position on the LNP’s Queensland ticket, also called for a dramatic cut in company tax rates and cast doubt over Russia’s involvement in a chemical attack in the UK last year.

Mr Rennick reportedly made the child care comments on Facebook in response to the opposition’s pledge last year to extend subsidised child care to three-year-olds.

“The cynic in me suggests this is another attempt by Labor to strengthen the role the state has in raising a child at the expense of the parents,” he wrote.

Labor’s campaign spokesman Jim Chalmers said the comments showed the Liberals were “spectacularly out of touch”.

“These guys are from another planet,” he told reporters in Logan on Monday.

Mr Chalmers accused Mr Rennick of wanting to pay for a tax cut for the top end of town by cutting early education, which the LNP candidate thought was a conspiracy.

“This isn’t some fringe character in the Liberal Party, this is a guy who is in a winnable position on the Senate ticket,” the Labor frontbencher said.

“Malcolm Turnbull was absolutely right to say the extreme right-wing of the Liberal Party has taken over.”

Mr Rennick has also backed away from an earlier statement in which he said a company tax rate of 12 per cent and a withholding tax rate of 15 per cent would combat tax avoidance.

“Definitely not 12 per cent and 15 per cent. I’m not into racing to the bottom,” he told the ABC.

“30 per cent and 25 per cent are low enough for the time being,” he added, referring to the rates currently legislated under the Coalition.”

In October last year, Mr Rennick told The Australian he took “with a grain a salt” the British government’s finding that Russian agents were responsible for Salisbury chemical weapons attack.