Prime Minister Tony Abbott has once again distanced himself from Liberal senator Cory Bernardi after the backbencher called for a new debate on abortion, railed against ''non-traditional'' families and called for more flexible industrial relations laws.

Senator Bernardi, a former parliamentary secretary to Mr Abbott, made the controversial comments in his new book, The Conservative Revolution, and stood by them in an interview on ABC TV on Monday.

In his book, Senator Bernardi accuses some women of using abortion as ''an abhorrent form of birth control'' and branded those who advocate for abortion to be available as ''pro death''.

Senator Bernardi writes that the ''death industry'' carries out 80,000 to 100,000 abortions each year. However there is no authoritative or complete count of the number of abortions, because terminations paid for under Medicare are recorded under the same code as a variety of other operations.

The South Australian senator also calls for the traditional family model to be restored to ''prime position'' over other family arrangements such as step families, same-sex and single families.

Opposition Leader Bill Shorten said as a stepfather he was offended by Senator Bernardi's suggestion that families such as his were ''somehow inferior''.

''Cory Bernardi's comments on what he regards as 'non-traditional families' are offensive,'' Mr Shorten said in a statement.

Senator Bernardi also called for more flexible workplace laws, saying some parts of John Howard's WorkChoices laws should be revisited.

''Surely an employee should be free to negotiate an acceptable workplace agreement directly with their employer … free from government or union interference,'' he writes.

''Small business needs to be empowered to hire and fire employees free of illegitimate government interference.''

The comments are likely to prove an unwelcome distraction for Mr Abbott, who has sought to neutralise the issues of industrial relations and abortion.

Mr Abbott's spokeswoman issued a one-sentence statement on Monday: ''Senator Bernardi is a backbencher and his views do not represent the position of the government.''

Senator Bernardi, who was re-elected to the Senate in last year's election in the No.1 position on the Liberal Party's South Australian Senate ticket, served as parliamentary secretary to Mr Abbott as opposition leader for more than two years, until he was demoted in 2012 for a speech in which he said sanctioning of same-sex marriage would lead to demands to legalise bestiality.

In 2010, Senator Bernardi called for a ban on wearing the burqa in public, and in 2011 he declared it was ''wrong'' for the government to pay the funeral expenses of asylum seekers who had drowned.

Tony Abbott Keeps Distance From Cory Bernardi Abortion Comments