A ROYAL commission to investigate the responses of religious, state and community groups to acts and allegations of child sexual abuse will be appointed by the end of the year.

Prime Minister Julia Gillard announced on Monday she would ask Governor-General Quentin Bryce to set up the inquiry, which would have no deadline and could run for years, amid calls for a national response by federal Labor, independent and Greens MPs.

"Any instance of child abuse is a vile and evil thing. Australians know that," Ms Gillard told reporters in Canberra on Monday.

"Australians know, from the revelations that they've read in recent weeks, that too many children have suffered child abuse but have also seen other adults let them down.

"They've not only had their trust betrayed by the abuser but other adults who could have acted to assist them have failed to do so."

She hoped the royal commission would help heal victims and ensure child abuse "never, ever happens again".

The broad inquiry will cover religious institutions of all denominations, state institutions, schools, not-for-profit groups such as scouts and sporting clubs, and also look at police responses.

"It's not just the evil of the people who do it, there has been a systemic failure to respond to it and to protect children," Ms Gillard said.

"We need to learn the lessons about how institutions can best respond when there are allegations of sexual abuse of children."

The move is likely to win political support, since Opposition Leader Tony Abbott said earlier on Monday that any investigation of child abuse should be wide-ranging and not focussed on just the Catholic Church.

The church currently faces a special commission in NSW to investigate allegations of abuse by clergy in the Hunter region and a possible cover-up.

A Victorian parliamentary inquiry is already examining sexual abuse by clergy in that state.

Attorney-General Nicola Roxon and the acting minister for families, Brendan O'Connor, will work with the premiers and chief ministers, victims' groups, religious leaders and community organisations in the next few weeks to establish terms of reference for the commission.

Ms Gillard said she expected the work would be finalised, and the commissioner or commissioners be appointed, by the end of the year.

She spoke with NSW Premier Barry O'Farrell and Victorian Premier Ted Baillieu on Monday to discuss how a national royal commission would fit in with their state-based inquiries.

But she stressed the commission was not targeted at any one church and said the Catholic church's senior cleric in Australia, Cardinal George Pell, had indicated "he's taking a very co-operative attitude".

Mr O'Farrell welcomed the announcement, telling AAP, "These heinous offences don't stop at state boundaries."

Ms Gillard said it was "not knowable" how long the inquiry would run but it would report back regularly to government.

"It should take the time necessary," she said.

Funds for the investigation will be provided in the 2013-14 budget in May.