Pauline Hanson has blindsided Prime Minister Scott Morrison by voting down his union-busting integrity bill, ending a horror week dominated by the ‘doctored documents’ police probe into Energy Minister Angus Taylor’s office.

Labor moved on Thursday night to ‘ground’ the trouble-prone minister by refusing to grant him a parliamentary pair for his vote during a planned overseas trip, in an attempt to force Mr Taylor to remain in Parliament and under scrutiny.

The Morrison government pledged to revive the union crackdown legislation on Thursday night after the One Nation leader shocked the government by voting with Jacqui Lambie, Labor and the Greens in a surprise move slammed as “a win for union thuggery”.

Senator Hanson blamed the “rampant white-collar crime exposed, involving tens of millions of breaches by Westpac, with no effort from the bank or this government to deal with their illegal actions” as a decisive factor.

Senator Jacqui Lambie and Senator Pauline Hanson before the vote on the Ensuring Integrity Bill in the Senate on Thursday. Photo: AAP

“The PM came out and said “it’s not up to us to deal with it, it’s up to the board to deal with the banks – but that’s not good enough,’’ Senator Hanson said.

“This is a warning shot across the bows of the unions and the government.”

But she did not rule out backflipping on her decision in the future despite her refusal to back “one rule for white-collar crime and much harsher rules for blue-collar crime”.

“Let this be a warning shot across the bows to all union bosses to get their act together and a second shot across government bows to clean up the white-collar crime,” Senator Hanson said.

Attorney-General Christian Porter issued a ‘please explain’ after the vote, which resulted in a stalemate with 34 votes each, meaning it was lost.

“It’s for Pauline Hanson to ­explain why she voted against a bill that met every requirement she sought through extensive consultation,” Mr Porter said.

“This is important reform which seeks to ensure that registered organisations obey the law.

“It is as simple as that. We remain committed to this reform and will be seeking to reintroduce the bill at an appropriate time.”

Australian Industry Group chief executive Innes Willox said the result was disappointing because it left the CFMMEU to continue “law-breaking and to treat the fines imposed by courts as just the cost of doing business”.

ACTU secretary Sally Mc­Manus said the proposed laws were “anti-union, anti-worker attack”.

“I’ve got a message for Scott Morrison: Don’t mess with working people,” Ms McManus said.