More claims of bullying involving embattled Sydney MP Emma Husar have emerged as Labor figures lock in behind her.
The western Sydney federal backbencher is facing an internal NSW Labor investigation into allegations she bullied and harassed about 20 former electorate office staff.
Peter Gray, the field director for Ms Husar's unsuccessful 2015 bid for the state seat of Penrith, told the Sydney Morning Herald he was hospitalised for four weeks after bullying in her office.
"No matter what I did, it was never enough," Mr Gray told Fairfax Media.
"Emma was giving me all these demands and had all these high expectations."
The newspaper reports Mr Gray's allegations are now being examined as part of the bullying investigation.
But incoming Labor party president Wayne Swan rejects suggestions the Lindsay MP should resign, saying she was entitled to "natural justice".
"The truth is there is a process going on. It's been done in good faith, and Emma is entitled to natural justice," he told ABC radio on Friday.
Barrister John Whelan is investigating the claims, which include allegations that Ms Husar's staff worked as child minders and picked up her dog's faeces.
A string of government MPs have called on Ms Husar, 38, to be sacked should the allegations by staff be proven.
Mr Swan said he only found out about the allegations "like most people in the country and most people in the Labor party" from media reports last week.
Labor leader Bill Shorten says he found out about the investigation when he was contacted by a media outlet last Wednesday.
But Prime Minister Malcolm Turnbull has said Mr Shorten's explanation "stretches credulity".
