Voter turnout in Ireland's referendum on the EU Fiscal Treaty has been reported as low across the country.
With polling stations open until 10pm and counting of ballots to start tomorrow morning, only about a fifth of the 3.1 million electorate have had their say.
Taoiseach Enda Kenny was among the first to cast his vote as to whether the country should ratify the controversial agreement to impose stricter budget controls.
Turnout in Dublin reached about 20% before teatime, with averages in the north west counties between 14% and 20%, and the Leinster region just below 20%.
The earliest indication of the result is expected no sooner than mid-morning tomorrow, when the political tally men start estimations from the 43 constituencies.
Turnout is crucial with low voter numbers in two previous European referendums giving the anti-treaty side a huge boost.
Irish voters have rejected the last two at the first vote only to accept the EU reforms in a re-run the following years.
Mr Kenny cast his ballot at St Patrick's National School in Castlebar, Co Mayo alongside his wife Fionnuala while his Tánaiste Eamon Gilmore voted in Shankill, south Dublin this morning.
Elsewhere, Sinn Féin president Gerry Adams, one of the key figures in the anti-treaty camp, was out early casting his ballot in the constituency of Louth where he moved to from Belfast to contest the 2011 General Election.
Last night both Mr Kenny and Mr Adams made their final appeal for support.
The Taoiseach said a strong Yes would send a message that Ireland is on the road to the recovery and that it would help continue the strong flow of investment into businesses seen over the last few months.
"While there are still difficult challenges ahead, I hope people will vote Yes to continuing the progress we've made together," he said.
Mr Adams' final message to voters warned that the treaty would not solve the eurozone crisis and would put into the Constitution the failed austerity policies.
"I ask Irish citizens not to be bullied, not to give their democratic rights away, not to give up their say over Irish economic policy and not to write austerity into the Constitution," he said.
Shortly after polling stations opened there was a security alert outside the constituency office of Sinn Fein's vice president Mary Lou McDonald.
Army bomb experts were sent to the scene at North Strand Road, in north Dublin, just after 10am to investigate a suspicious device which was later made safe. The party confirmed the device had been a hoax pipebomb and that graffiti had been daubed on the front of the building.
In a break from tradition, State broadcaster RTÉ will not be reporting an exit poll but three recent opinion polls have shown a 60/40 split in favour of the treaty among Irish voters.
The Taoiseach has said he was confident, but never over-confident, before polling day but his number two Mr Gilmore refused to make a call.
Ireland is the only country in Europe holding a referendum on the treaty.
The treaty will come into effect with the support of 12 states, with or without Irish support.
Twenty five of the 27 European Union states have accepted the text of the treaty - with the exception of the UK and Czech Republic.
Only three states have ratified the treaty in full - Greece, Portugal and Slovenia - while Germany, Poland, Latvia, Romania, Austria and Denmark have begun the process.
If passed, the treaty will see stricter budgetary rules imposed on member states and penalties for those that fail to meet them.
The objective of the treaty is also to keep a control on deficits and ensure greater checks and balances are in place for money in and out of each country.
The Yes camp, including Fine Gael, Labour and Fianna Fáil, has argued that ratification will ensure Ireland has access to emergency funds from Europe should it require a second bailout.
Our live blog is up and running here. We'll have live results and reaction through the day tomorrow.