In pictures: Ireland's Lisbon Treaty vote

Young girls look into a polling station as Irish people cast their vote at Mucklagh National School in Tullamore, Ireland (2 Oct 2009 )

European eyes are on the Republic of Ireland, where voters are going to the polls in a key referendum on whether to ratify the Lisbon Treaty on streamlining decision-making in the enlarged EU.

Nuns cast their vote at the polling station in Drumcondra Boys National School, Dublin (2 Oct 2009)

For the second time in under two years, around three million Irish citizens are being asked to determine the fate of the Lisbon Treaty - a 2006 agreement already backed by the majority of parliaments within the EU.

Irish Prime Minister Brian Cowen departs after casting his vote at the Mucklagh National School in Tullamore, Ireland (2 Oct 2009)

Back in June 2008, voters across Ireland rejected the treaty. Prime Minister Brian Cowen has said he is confident Irish voters will be in favour this time around.

A poster on a bus urging voters to vote 'Yes' on the Lisbon Treaty in Dublin, Ireland (1 Oct 2009)

In the weeks running up to the referendum the 'Yes' campaign has been in full swing. Opinion polls suggest a majority 'Yes' vote this time.

Ireland's Sinn Fein party leader Gerry Adams is urging voters to reject the Lisbon Treaty, speaking to the media during a press event in Dublin, Ireland (30 Sept 2009)

The Republic of Ireland is one of 27 countries to vote on the treaty. All parties in Ireland are pushing for a 'Yes' vote now except the nationalist Sinn Fein. It argues voting 'No' would secure a more democratic EU.

Thousands of people from the Irish Congress of Trade Unions (ICTU) march through Dublin city centre during a national day of demonstration in Dublin, Ireland (30 Sept 2009)

Ireland's economy has been sharply hit by the global recession. Mr Cowen said another 'No' vote would damage Irish hopes of reversing its recession and would plunge the EU into "extraordinary uncertainty".