Malcolm Turnbull’s effort to seize the economic agenda on the first business day of the new parliament was undermined late on Wednesday when the government was forced to correct an error in its “omnibus” savings bill.



The prime minister navigated early procedural turbulence on Wednesday, seeing off motions launched by Labor relating to a royal commission into the banking sector, and a separate foray on negative gearing.

Anticipating that Labor would attempt to challenge the prime minister’s authority on the floor of the parliament, the government unveiled a new investigation by the small business ombudsman to examine how banks treat their small business customers.

But the new inquiry may not be enough to head off a separate banking motion to be launched in the Senate on Thursday. That procedural foray looks as though it could succeed, and the Labor leader, Bill Shorten, is also due to meet with victims of banking scandals in Canberra on Thursday.

Turnbull fired up during question time, declaring the Shorten was intent on “posing as some sort of latter-day Jack Lang” – a populist champion of the battler and small business.

But Labor pointed out during question time that one of the government’s signature budget repair bills, the savings bill worth $6.1bn, appeared to have a $100m hole in the explanatory memorandum tabled in the parliament.

The omnibus bill was introduced by the treasurer, Scott Morrison, earlier on Wednesday. In the original explanatory memorandum accompanying the proposed legislation, item 11 claimed a saving of $405.6m from changes to student startup scholarships – but the sum of the annual savings, as reported, only adds to $298m.

Late on Wednesday, after the error was pointed out during question time, Morrison went back into the house to correct the . The Treasury issued a statement saying a computational error had caused the discrepancy.

The error takes the value of the savings measures in the package below $6bn. The new value of the package is $5.9bn.

In other developments on the first business day of the 45th parliament:

The Liberal senator Cory Bernardi introduced his private senator’s bill that would remove the words “insult” and “offend” from the Racial Discrimination Act, and Labor used question time to turn the spotlight on the issue.



The Indigenous Labor senator Pat Dodson urged the Senate to hold firm against any move to water down the act, urging the prime minister to be “unequivocal” in opposing the changes.



Labor opened a new front in the controversy over the leaked NBN Co documents, asking the privileges committee to examine whether there has been “improper interference”, or “attempted improper interference”, with Stephen Conroy’s free performance as a senator.



The Senate established an inquiry to examine what went wrong with the census. Labor, the Greens and several crossbenchers referred the matter for investigation, and a committee will examine privacy concerns as well as the technology issues.



A number of new parliamentarians made their first speeches, including the Indigenous Labor MP Linda Burney, and the Liberals Tim Wilson and Jane Hume.

The Labor senator Sam Dastyari also found himself in hot water over entitlements after a story published by Fairfax Media highlighting that he asked a communist-linked Australian-Chinese donor to foot an expenses bill when he exceeded parliamentary travel entitlements.

Dastyari was blasted in the Senate by Bernardi, who branded him the “Manchurian candidate”. Bernardi called for the Dastyari to step aside from the frontbench until he provided a proper explanation for his conduct.