"If we do not pay the debt off we cannot hold our head up as an Irish community," Mary Doherty, vice-president of the Sydney St Patrick's Day Committee, said.

The Sydney Irish's big day of the year, the 2016 St Patrick's Day parade, had to be cancelled after the volunteer committee running the celebration had run up debts of $170,000.

The  cancellation of the March 17 parade was a double blow to the Irish.

April 24 is the centenary of the Easter Rising when republicans led by Padraic Pearse seized Dublin's General Post Office in 1916, and proclaimed an Irish Republic.

The centenary is a seminal moment and the government in Dublin has set aside nearly $35 million to commemorate and called on the Irish diaspora around the world to remember those who fought for independence, and to reflect on the legacy of the last 100 years.

The Irish embassy in Canberra is involved in many projects to mark the centenary but few will be held in Sydney.

The main Sydney event will be the March 28 recitation of the Proclamation of the Republic outside the GPO and a screening of the film, A Terrible Beauty, at the NSW State Library.

But the cancellation of the St Patrick's Day procession has rained on the Irish parade.

The committee did not learn of the debt until December after the remaining volunteers jumped overboard and an emergency annual general meeting was held to elect a new committee and sort out the mess.

"The size of the debt was quite a surprise, I can tell you," committee president Robert Kineavy said.

"It was with much reluctance that we had to cancel the 2016 parade. Clearing the debt became our first priority."

About 80 people attended a public meeting at the Gaelic Club in Darlinghurst on Tuesday where the new committee was questioned about the debt and how it intended to run the parade in 2017.

St Patrick's Day parades were once an annual part of Australian life as the Irish and their descendants made a stand for the culture left behind but when the old sectarianism died out in the 1960s the parades with their floats, dancers, bands and ranks of marching Catholic school students faded into history.

In 1979, the Irish community in Sydney organised a St Patrick's Day Festival and it evolved into one of the world's largest. However, in 2014 a storm hit the parade and dealt a hammer blow to revenue at the Family Day concert in Hyde Park.

The committee went deeper in debt for the 2015 parade and then bailed out.

Mr Kineavy told the meeting that the new committee had managed to raise $70,000 in the two months since being convened.

Behind him were 32 white sheets of papers bearing the names of the Irish counties. When the meeting closed a woman took the stage and exhorted those present to "show the flag" and buy themselves one of the counties for $2000.

"C'mon boys, you can do it. Irish pride will help you dig deep," she cried.

Ten minutes later, the St Patrick's Day Committee had another $30,000 in the kitty.