Pope Francis is being called on to remove three cardinals from roles in the World Meeting of Families, taking place in Ireland next week.

It comes as the fallout continues from the allegations of the cover up of clerical sex abuse in Pennsylvania.

A grand jury investigation has alleged that 301 Catholic priests in the US state sexually abused children while serving in active ministry.

Investigators received 'detailed accounts' of more than 1,000 victims - with the grand jury saying it believes the actual number of victims was in the thousands.

The abuse is alleged to have occurred over 70 years in six dioceses.

According to the grand jury, most of the victims were boys, but some girls were also abused.

Attorney General Josh Shapiro outlined the findings of the grand jury investigation into six catholic diocese in Pennsylvania | Image: USA TODAY Network/SIPA USA/PA Images

Cardinal Donald Wuerl of the United States was one of those criticised in the grand jury report, over his handling of abuse claims.

He is due in Dublin for the Papal visit.

Campaign group, Ending Clergy Abuse, has written to the Archbishop of Dublin Diarmuid Martin outlining their demands.

Meanwhile, there is concern at the extent of the problem across the US.

Anne Barrett-Doyle is from BishopAccountability.org.

She says they are looking for the Pontiff to take action.

"They are calling for three cardinals to step back from their involvement in the World Meeting of Families - they have prominent roles there.

"We don't get reliable victim counts unless we have disclosure, so it's a vicious circle.

"If documents are not disclosed, if prosecutors don't do investigations, if the media doesn't have enough evidence to do their own investigations we have that circle of silence again.

"And that's effectively what we still have in some states of the United States".