President Mary McAleese, Taoiseach Bertie Ahern and Minister for Defence Willie O'Dea will lead a ceremony to mark the 91st anniversary of the 1916 Easter Rising outside the GPO in Dublin tomorrow.
The event is expected to attract thousands of spectators, although it will be on a significantly smaller scale than last year's 90th anniversary parade, which attracted more than 100,000 spectators.
Last year's parade also involved a march through Dublin by 2,500 members of the Defence Forces and veterans of peacekeeping missions.
This year's "static" march will see 350 Defence Forces personnel, including a brass band, a pipe band and representatives of the Army, the Air Corps, the Naval Service and the Reserve Defence Force, gather at the GPO in O'Connell Street.
It will be a troop-centred ceremony and will not feature Army tanks or gun carriages. However it will conclude with an Air Corps "fly past" involving four PC-9 training aircraft and four Air Corps helicopters.
The parade will be formed at 11.30am, with gardaí advising motorists that traffic restrictions and other diversions will be in place during the morning and early afternoon.
Mrs McAleese, flanked by a presidential escort, will arrive at the steps of the GPO shortly before noon, where she will take a guard of honour formed by 107 members of the Reserve Defence Force.
The central guard of honour outside the GPO will be drawn from cadets at the Military College in the Curragh.
A minute's silence will then be held, while at noon the national flag will be lowered to half mast. This will be followed by a short prayer service, the playing of a piper's lament, and the reading of the Proclamation.
After this, a wreath will be laid by Mrs McAleese in honour of those who died.
There will then be a minute's silence, after which a bugler will sound "last post", and the Tricolour will be returned to full mast. Amhrán na bhFiann will be played, and the Air Corps will perform its fly past.
The ceremony will conclude when Mrs McAleese enters the GPO, where a reception will be held for dignitaries. Relatives of those who took part in 1916 will be guests of honour at the reception.
Sinn Féin has also planned more than 100 Easter commemorations, including five on Sunday in Dublin, Belfast, Tyrone, Cork City and Waterford (Ardmore).
Sinn Féin president Gerry Adams will deliver an address at the Dublin event, which will assemble at 1.30pm at the Garden of Remembrance on Parnell Square and proceed to the GPO.