Democratic Alliance (DA) Minister of Parliament (MP) David Maynier was ordered out of the National Assembly on Thursday, after refusing to withdraw a statement in which he accused Defence Minister Lindiwe Sisulu of "telling a big political fib" to Parliament.

Maynier, who has taken to using members' statement time in the House to call on Sisulu to release interim reports of the national defence force service commission, earlier questioned reasons given by the defence minister for not doing so

"One of the many reasons in the minister's arsenal of excuses [for not releasing the report] was that there was no link between the interim reports and the Defence Amendment Bill, but... there is a link.

"The interim report itself contains a draft defence amendment bill. How is it then possible... if it is not linked?

"The fact is, the minister has been caught out telling a big political fib to this Parliament. And the minister should now take steps... to release the interim reports," Maynier said.

On a point of order from Deputy Basic Education Minister Enver Surty, who questioned whether it was possible to "attack the integrity of a member of this House without bringing about a substantive motion", Speaker Max Sisulu said that he would study the matter and come back with a ruling.

At the end of members' statement time, he delivered one.

"Saying the Honourable Minister of Defence and Military Veterans told this Parliament 'a big political fib' is tantamount to saying the minister lied to Parliament - a serious charge, and one that is definitely unparliamentary, and in this case, without any substantive motion," he ruled.

He then asked Maynier to withdraw the statement.

"Speaker, with respect, I refuse to withdraw the statement," Maynier told him, and was then asked by Sisulu to leave the chamber, which he did.

Maynier has used the past two members' statement times to controversially read extracts from a leaked copy of the interim report.

This has included reference to its findings that the combat readiness of the SA National Defence Force's state of combat readiness is "not quite as good as it should be", and that low morale in the force "could even threaten state security".

In a statement issued later on Thursday, DA Chief Whip Ian Davidson said that the party stood fully behind Maynier and his statement.

"The DA stands fully behind shadow defence minister David Maynier MP, and the comments that he made in Parliament today regarding Defence Minister Lindiwe Sisulu's handling of the national defence force service commission report.

"Mr Maynier's expulsion from Parliament, by Speaker Max Sisulu, is unacceptable. It is Minister Lindiwe Sisulu's behaviour that is unparliamentary, and warrants rebuke.

"Minister Sisulu has repeatedly been uncooperative with Parliament, contravening her constitutional duties to uphold the principles of accountability and transparency."

Davidson said it was only fair and right that such conduct was brought to Parliament's, and by extension, the South African public's attention.