Update - 3.07pm: The Dublin Region Homeless Executive says it has sourced a large number of additional emergency accommodation to cater for families during the Pope visit.
It says it has been working closely with private accommodation providers to ensure existing hotel and B&B bookings will not be adversely affected.
It has also increased staffing of its freephone number, 1800 707 707, on Saturday and Sunday and its outreach teams will be on the streets engaging with those at risk of sleeping rough.
The organisation said: "The DRHE is aware of the difficult circumstances that families experiencing homelessness have to face and we will continue to monitor the demand for emergency accommodation during this time.
"We will endeavour in the first instance, to accommodate any families that newly present during the Papal visit within the Dublin Region.
"However as part of our additional contingency measures, a certain number of spaces are located outside of the Dublin Region, these will be utilised only when absolutely necessary."
The World Meeting of Families officially opens today.
Bells will ring this evening in Catholic cathedrals across Ireland's 26 dioceses to mark the start of the gathering.
Pope Francis will join the event on Saturday, and will celebrate its closing mass in the Phoenix Park in Dublin on Sunday.
Preparations have been overshadowed by revelations about the church's handling of clerical sex abuse.
Maeve Lewis from campaign group One in Four says the celebration will ring hollow for many abuse victims.
"I'm sure people who are attending the mass in the Park or the other events do not mean in any way to add to the suffering of the survivors," said Ms Lewis.
"But in many ways, that is what's happening because people feel that their suffering is just being ignored in the middle of this big international celebration."
Yesterday, Pope Francis issued a letter to Catholics around the world condemning the "crime" of sexual abuse by priests and subsequent cover-ups, saying: "We showed no care for the little ones; we abandoned them."
- Digital Desk