It isn't hypocritical to support Liberal senator Mary Jo Fisher while criticising Labor MP Craig Thomson, federal coalition MP Scott Morrison says.

Senator Fisher was on Friday found guilty of assaulting a security guard at an Adelaide supermarket in December, but no conviction was recorded or penalty imposed because she was suffering depression at the time.

Opposition Leader Tony Abbott said the lack of a conviction meant Ms Fisher would not be disqualified from retaining her senate seat.

"The thoughts of her colleagues and friends are with Mary Jo at this difficult time," he said in a statement.

Asked if the coalition's position was hypocritical after its long campaign against former Health Services Union boss Mr Thomson - who is alleged to have misused a union credit card, but never charged - Mr Morrison said: "I think these are very different matters.

"I don't believe there is a comparison between the events.

"If the government wish to compare these events, then they're at liberty to do so. But I think on any fair assessment of these things that the events are quite different," Mr Morrison told reporters in Sydney on Friday.

"I'm pleased for Mary Jo, I'm pleased for her family, and we're all pleased to see her back at work doing the job that I know she is passionate about."