A Coalition MP says politicians should be subject to random drug and alcohol screening tests, especially if they have been speaking in Parliament's chambers.

Queensland Nationals MP Llew O'Brien has echoed calls made on May 10 by Senator Jacqui Lambie for drug testing of welfare recipients to be extended to politicians.

He made the comments while discussing the Federal Government's plans to conduct random drug tests on some welfare recipients.

Mr O'Brien, a former police officer, told the ABC he supported drug testing for politicians and said random breath tests for alcohol should also be a "no brainer".

"Politicians have a great deal of responsibility particularly when they're in the chamber and they have the protection of parliamentary privilege," he said.

"A politician can say something under parliamentary privilege without fear of prosecution, or defamation, and really, they could say something that could ruin someone's life.

"There have been times when people have been named unfairly or incorrectly and it's had a very significant and damaging impact on their life.

"If you're in a position such as that, I think the community, in this day and age, should be satisfied that you're not impaired by alcohol of drugs while you're in there."

Mr O'Brien noted alcohol was available with lunch at Parliament.

"There's a member dining room that serves alcohol, I haven't seen people or politicians stumbling around drunk," Mr O'Brien said.

"But at the same time, as a policeman, the person walking from the pub to their car isn't always staggering around drunk.

"But when they blow into the bag, they've got a level that would indicate that they should not be on the roads."

Llew O'Brien (right) was a member of the Queensland Police Service before entering Parliament. ( Supplied: Facebook )

The first-term MP said it was the right time to be discussing the idea, on the back of the welfare announcement in the budget.

On Tuesday, Treasurer Scott Morrison outlined the Government's welfare reforms, which included plans to drug test 5,000 welfare recipients in a trial scheme.

Those who test positive will be placed on a cashless debit card for their payments, or even have benefits temporarily stripped.

"We want to support jobseekers affected by drug and alcohol abuse, but to protect taxpayers, it has to be a two-way street," he said.

"We will no longer accept, as an excuse from repeat offenders, that the reason they could not meet their mutual obligation requirements was because they were drunk or drug-affected."