A Labor senator has described his battle with alcoholism four decades ago, making a plea for the government to dump harsher conditions for jobseekers suffering from addiction.

Opposition frontbencher Doug Cameron was speaking in support of a Greens push, which ultimately failed, to dump tightened measures for welfare recipients looking for work.

The changes to social security laws limit drug and alcohol addiction to a one-off reasonable excuse for not meeting jobseeking obligations.

"As someone who is an alcoholic, as someone who hasn't taken any alcohol for about 40 years I know how difficult it is," Senator Cameron told parliament on Monday night.

"I certainly don't understand how forcing someone into abject poverty helps their drug or alcohol addiction."

The veteran Labor senator said anyone with an understanding of addiction knew it was a health issue, which could be worsened by taking people's income away from them as a punishment.

"I was lucky. I had a family who supported me. I maintained my job during the period of alcohol addiction," Senator Cameron said.

"If you don't have that, this proposition only makes matters worse for people."

Greens senator Rachel Siewert led the move to disallow changes to social security laws including removing tighter jobseeking requirements.

She warned the tighter restrictions on people looking for work would make a failing system worse.

"These measures will make our already punitive income support system even more punitive," Senator Siewert said.

The federal government has previously argued removing the ability to repeatedly use drug and alcohol dependency as an excuse for failing jobseeking obligations would lead more people to getting help.

Jobseekers who participate in treatment have that count towards meeting their mutual obligation requirements.