Update 4.35pm: Thousands of people who turned out for the Stand4Truth protest are now walking together towards the last Magdalene Laundry to close in Ireland.
The institution on Seán McDermott Street closed in 1996.
Tens of thousands of so-called fallen women were effectively incarcerated in Magdalene laundries across Ireland.
Former taoiseach Enda Kenny issued an apology to the woman held in the laundries. Many have now received compensation from the state.
The Stand4Truth protest will hold a rally at the gates of the former laundry.
The building is now owned by Dublin City Council, who have offered it for sales. It is the last former laundry in Ireland that remains in public ownership.
Survivors are campaigning for the building to be kept in public ownership and turned into an interpretive centre.
Update 3.22pm: Thousands gather at Stand4Truth protest in Garden of Remembrance
Thousands of people have turned out in Dublin City centre for a protest, just a few miles from Phoenix Park where Pope Francis is celebrating Mass.
The Stand4Truth rally at the Garden of Remembrance was timed to start at 3pm, the same time as the pontiff’s Mass.
Thousands are standing before a mobile stage filling Parnell Square East. Some are holding banners which read “Secular Justice For All, Truth Justice Love and Church Without Abuse”.
An organiser said the turnout had surpassed his expectations, and thanked those in attendance.
One of those speaking from the platform, Sarah Clancy, told the gathered audience “we have a right to be angry”, to rousing cheers.
A number of artists will perform music and poetry at the event.
Belfast singer Brian Kennedy performed the John Lennon classic Imagine at the rally.
Before a crowd of thousands, Kennedy revealed he had written a new verse for the song – which he said he was singing in the direction of the Phoenix Park.
The protest is taking place at the same time as Pope Francis celebrates Mass at the park.
The new verse began: “Imagine there’s no paedophiles, I wonder if you can. No need to rape or vilify, all of these thousands can.”
Update 2.50pm: Protesters are gathering at the Garden of Remembrance on Dublin’s O’Connell Street for a demonstration to coincide with the Papal mass at the Phoenix Park.
A number of musicians including Hozier, Mary Black and Liam O'Maonlaí will perform at the Stand4Truth event in solidarity with clerical abuse survivors.
The group will then march to the site of the former Magdalene Laundry on Sean McDermott Street.
The organiser of the event Colm O'Gorman says the turn out is phenomenal.
"I've never seen anything like it," said Mr O'Gorman.
"We met for the first time a week and a half ago and just look out there now at what's been put together.
"The artists who absolutely said they wanted to come along and help us build the sense of occasion and spirit and intent that we wanted to build here
"The people who are turning up...it's mindblowing. It's wonderful. I mean, this is Ireland. It's phenomenal."
Earlier: Protest march for clerical abuse victims to coincide with Papal mass
A solidarity march for victims of clerical abuse will take place today to coincide with Pope Francis' Mass in Dublin's Phoenix Park.
The Stand4Truth march will begin at the Garden of Remembrance on Parnell Square at 2.30 pm this afternoon and organisers of the event say they expect thousands of people to take part.
Solidarity in the search for Truth, Justice, & Love today at the Garden of Remembrance. Open to all & the rain is to lift by then. Starts 2:30 & has the potential to offer community & healing. In gratitude to @Colmogorman for the opportunity to #Stand4Truth while #PopeInIreland pic.twitter.com/HvWHGT31yv— Deirdre Murphy (@deirdremurphy01) August 26, 2018
Among those attending the march are singers Hozier, Mary Black and Liam O'Maonlai - who will perform on stage.
It will also feature spoken word performances by theatre-maker Grace Dyas, poet Sarah Clancy and activist Colm O’Gorman.
The crowd will then walk silently to Sean McDermott Street to the last remaining Magdalene Laundry.
They will be able to leave messages of support there, the focus of which will be a commissioned art piece by artist Will St Leger.