Comedian Tim Minchin has penned a scathing song slamming the most senior member of the Catholic Church in Australia, calling Cardinal George Pell 'scum' and a 'coward'.

In his new expletive-filled charity single, 'Come Home, Cardinal Pell', Minchin urges Cardinal Pell to make the journey back to Australia and testify at the Royal Commission into Institutional Responses to Child Sex Abuse.

Cardinal Pell is currently in Rome and claims he is too ill to fly to front the commission.

He has been under fire since allegations emerged about him turning a blind eye to the abuse in Ballarat, in central Victoria.

On Tuesday, Minchin took aim at the cardinal and labelled him a 'pompous buffoon'.

'Couldn't you see what was under your nose, Georgie... Is it true that you knew but you chose to ignore or did you actively try to keep it buried?' the comedic singer also asked the cardinal.

'And years later, when survivors, despite their shame and their fear stood up to tell their stories, I mean, with all due respect, dude, I think you're scum.'

In his signature tongue-in-cheek fashion, Minchin admits he is not the 'biggest fan' of Pell's religion and did not hold back his feelings by adding: 'I personally believe that those who cover up abuse should go to prison.'

He added: 'Your time is running out to atone, Georgie. I think the Lord is calling ya home, Georgie. 

'Perhaps he could forgive even you if you just let them know what you knew.'

The song's proceeds will go towards funding trips for child sex abuse survivors to go to Rome and give them the opportunity to sit in front of Cardinal Pell if he gives his evidence via video link.

Media personality Meshel Laurie has set up a gofundme page for the campaign and it has raised more than $100,000 in two days.

But conservative media personality Steve Price has defended Cardinal Pell against Minchin's musical attack.

Appearing on Network Ten's The Project on Tuesday night, the radio host slammed the comedian over his song.

Price - who appeared on the panel alongside hosts Carrie Bickmore, Peter Helliar and Waleed Aly - criticised the tune as an 'insult' after it debuted on the program.

'Look, obviously, Tim Minchin feels really strongly about that but I just think it's really disgusting the way he resorted to personal abuse there of George Pell,' Price said.

'To write a song like that and use your talent to just simply abuse someone from a distance, I think is just pathetic.

'This is the same Cardinal that came twice to the royal commission and appeared, looked people in the eye who were alleging that they'd been abused by priests.

'He's done it twice and he's convinced the commissioner that he's unwell in Italy and he can't fly. You gonna force this guy to get on the plane? Minchin needs to tone that down... in my view.'

But Helliar was quick to respond to the criticism, saying Mr Minchin was entitled to 'a freedom of speech' through his new tune.

'He obviously wanted to make a point about a serious issue, and he's obviously made a point,' Helliar said.

But Price responded: 'George Pell said he never knew what was going on in Ballarat. He said persistently under oath.'

Following the song's debut, the response has been met with mixed comments on social media, with some throwing their support behind Minchin while others slammed Price's rant.

Giulio Reginato tweeted: 'Tim Minchin's new song? This that what they mean by "calling a spade a spade"? Brilliant !! ISteve Price what planet r u [sic] on??'

Christopher Bendall said: 'Incredible song from @timminchin demanding answers from Cardinal Pell over Church abuse cover-ups.'

Paul Lowe posted: 'Steve Price, why are you supporting Pell? Obviously you support the biggest cover up in history by the Catholic Church.'

Steves Corner wrote: 'Shocker! Steve Price sticking up for Pell.' 

Stephen Matthews said: 'Steve Price clearly lives on another planet. Get some perspective mate.'

However, many defended Mr Price's opinion on the song, with some calling it as 'marvellous'.