The status is the highest designation that can be conferred on a site of historic importance in the state. The decision on 16 Moore Street will be confirmed when Ahern delivers the annual Liam Mellows commemoration speech at Castletown, Co Wexford. The register of national monuments includes Kilmainham Gaol in Dublin and Padraig Pearse's Cottage in Rosmuc, Co Galway.

"From a historical, social and political standpoint, 16 Moore Street is of significant national importance, " the Taoiseach will say today.

Documents have established that 16 Moore Street and adjacent buildings were the last to be occupied by the leaders of the 1916 rebellion when they retreated from the GPO at the end of Easter week. Pearse, along with other figures including the wounded James Connolly, Thomas Clarke, Joseph Plunkett and Sean Mac Dermott, took refuge in the building which was then home to O'Hanlon's fishmonger business.

With no hope of escape . . . and a likelihood of further casualties . . . Pearse gave the surrender order from 16 Moore Street. One account from the time recalled Pearse comforting a wounded British soldier in the building before authorising Elizabeth O'Farrell to take a white flag to the British forces positioned at the top of Moore Street. After half an hour, O'Farrell returned to 16 Moore Street with the British demand for an unconditional surrender. Pearse then left the building and handed over his sword in a formal act of surrender.

The building, which has fallen into disrepair in recent years, was listed for demolition by Dublin city council in 2003. Council officials wanted to knock down the house as a part of a redevelopment plan for the north city centre area which would have connected Moore Street with O'Connell Street. The plan met with strong resistance from several groups, including An Taisce and a majority of the members of Dublin city council. Campaigners lobbied for the preservation of the building and its redevelopment as part of a new 1916 museum. The campaign was stepped up this year with the 90th anniversary of the Easter Rising.

With confirmation of the designation of 16 Moore Street as a national monument, progress is now expected on the development of the O'Connell Street/Moore Street area as a 1916 quarter. In his speech today, the Taoiseach will indicate his backing for a redevelopment of the site of the GPO in time for the 2016 centenary anniversary. He will confirm that this redevelopment will include "a memorial dedicated to the Rising as well as a museum of celebration of Irish progress and achievement across a broad spectrum".

The Taoiseach will also confirm that funding will be provided to ensure that historically important records of the military pensions archives will be available in digital form by 2016. These records, which include 17,000 successful applications for the Old IRA pension, give a unique insight into the lives of the people who were involved in the War of Independence. In last week's budget, a special provision of 100,000 was allocated to allow work to start on the project.

The Taoiseach will also use his speech today to reflect on the political stand-off between Sinn Fein and the Democratic Unionist Party. "It has been a long and at times frustrating journey. But the obstacles that stand in the way of final resolution are very, very few, " Ahern will say. He will also deliver a strong message to the Sinn Fein leadership to call a party conference "at which the policing issue is definitively and successfully addressed".

He will say: "Given the St Andrew's Agreement timetable, it is clearly important that this ard fheis is held as soon as possible, thereby creating a new environment where policing in Northern Ireland, which since the Patten Report has been reformed comprehensively, is endorsed and supported by all."