The Morrison Government has voted against an inquiry into a million dollar legal fund set up for former attorney-general Christian Porter.

Mr Porter quit the frontbench in September after revealing that his legal fees in a defamation case against the ABC would be paid by a secretive blind trust from anonymous donors. 

Mr Porter says his disclosure was within parliamentary rules, but refused to reveal who contributed to the legal fund. 

On Monday, Speaker of the House Tony Smith was asked to consider allowing debate on whether Mr Porter could be referred to the House privileges committee, which can consider whether he breached parliamentary rules.

“Based on my careful consideration of all of the information available to me, I am satisfied that a prima facie case has been made out,” Mr Smith told the House, allowing the Labor motion to be debated.

“An opinion by the Speaker that a prima facie case has been made out does not imply a conclusion that a breach of privilege or contempt has occurred.

“In giving precedence for a motion to be moved, I'm simply allowing the House the opportunity to consider a motion immediately, and debate and decide on whether the matter should be referred to the committee for inquiry and report.”

The motion was defeated 52 to 49. Some analysts have been astounded, as it is virtually unprecedented for the House to block a referral to a committee after the Speaker finds a prima facie case.

The privileges committee can still run an investigation, but needs a vote of parliament to report back its findings to the House.

Mr Porter sued the ABC for defamation after he revealed himself to be the MP at the centre of historic rape allegations, but the case was settled before going to court.