Liberal senator Arthur Sinodinos has broken government ranks to call for an increase to the Newstart allowance.

Senator Sinodinos said the jobless allowance, which has been going backwards in real terms for 25 years, should be higher.

"That's probably a slightly radical thing for me to say here," he told the ABC's Q&A program on Monday night.

"I'm putting a personal view, I'm not necessarily talking on behalf of the government here. But my observation is that this does raise an issue that should be considered at some stage."

People on the unemployment benefit receive $538.80 per fortnight. In comparison, aged pensioners take home $834.40.

Welfare advocates have described the Newstart allowance as "unnecessarily cruel", but the coalition government has steadfastly resisted calls to raise the rate.