Lord Mayor of Dublin Christy Burke has said the death overnight of a homeless man on the streets of the city was a national disgrace.

The man's body was discovered on Molesworth Street, less than 50 metres from Leinster House, at around 8.30am.

Gardaí said they are investigating the death.

The Dublin Simon Community has said there is very little accommodation for anyone living on the street seeking shelter because of economic homelessness.

Its chief executive, Sam McGuinness, said that emergency accommodation is becoming long-term accommodation.

Despite processes in place to try to facilitate people during the shortage, he said that people have stopped trying.

Speaking on RTÉ's Six One News, he said that housing organisations are using their own funds to source and buy accommodation, but that a significant amount of further accommodation is needed.

Mr McGuinness said he believes he knows the man who died on the street overnight.

He said it is understood that the man was booked into accommodation last week, but did not show up.

Director of Advocacy at Focus Ireland Mike Allen said it is a terrible tragedy that someone should die in these circumstances while living on the street.

"The reasons why people end up sleeping homeless are complex, and mental health issues and addiction issues, as well as housing problems, play a part," he said.

"Focus Ireland and the Peter McVerry Trust last month started a housing first programme in Dublin and over the next three years they will be working to provide homes for all people who are sleeping rough.

"Rent supplement and rent freezing wouldn't make a difference to this man, but the Government’s failure to move on them means the entire homeless sector is under enormous pressure."

Speaking on RTÉ News at One, Sister Stanislaus Kennedy of Focus Ireland said it was an awful tragedy that someone would die in such terrible circumstances and so publicly.

"I think what it says to us that this man like so many others who are sleeping out are a sign of the failure of the State ... of the failure of the State in the past and in the present to offer them the support they needed to live independently."

Sr Kennedy said many people sleeping rough needed specific supports and help and she said enough is not being done to help them.

"The answer was not more emergency accommodation but providing more homes.

"The answer is making sure that people who are leaving the care of the State, whether that be in hospital or childcare or prisons, that they're not discharged into homelessness", she said.

Ahead of tonight's meeting of the Dublin City Council, Fianna Fáil councillors lodged an emergency motion calling on Taoiseach Enda Kenny to reschedule an emergency meeting on homelessness cancelled by Minister for the Environment Alan Kelly.