Bill shorten has backed a Labor candidate who shared porn and rape memes and insulted working class voters on Facebook.
Luke Creasey, 29, has refused to step down as Labor's candidate for Melbourne after it emerged he made offensive posts in 2012.
At a press conference in Macnamara, Victoria on Friday morning, Mr Shorten implied Mr Creasey was too young to be held responsible for the posts.
The Labor leader said: 'I'm not going to defend the remarks. [They were] shocking and stupid.
'He has also come forward and said he was 22 at the time, seven years ago. He is mortified, as he should be.
'He doesn't want to cause any embarrassment and he doesn't hold those views now. He has apologised deeply and he certainly doesn't hold those views now.'
Rape jokes: Luke Creasey, 29, has refused to step down as Labor's candidate for Melbourne
In the posts in 2012, Mr Creasey shared one meme titled 'overly attached girlfriend' which read: 'Hey I just met you / If you don't date me / You'll go to prison / I'll say you raped me.'
Another meme he shared, designed to insult people with concerns about immigration, said: 'Complains refugees waste tax dollars / Uses Centrelink money to buy drugs and alcohol.'
Mr Creasey also insulted working class voters in Scott Morrison's south Sydney seat with a post that read: 'Endorsement by those who call the Sutherland Shire home is not something that anyone with decency should aspire to.'
He also shared a link to porn involving the sexual kink pegging.
Greens MP for Melbourne, Adam Bandt, demanded Mr Creasey's resignation.
'Just a few years ago, while I was representing Melbourne's values in Parliament, my Labor opponent was sharing rape jokes,' he said.
'Violence against women in any circumstances is unacceptable. I think Mr Creasey needs to reconsider whether he remains as the Labor candidate.'
At the conference on Friday morning, a reporter asked Mr Shorten: 'At what age does the young and dumb defence cease to apply?'