The Lisbon Treaty will threaten Ireland's neutrality, weaken the country's voice in the EU and undercut public services, Sinn Féin's Mary Lou McDonald warned tonight.
The Dublin MEP urged people to vote no in the upcoming referendum on the treaty, branding 'Yes' camp claims that a rejection would result in economic woes as scaremongering.
Addressing delegates at the party's Ard Fheis in Dublin, she said the Irish public was in a prime position to reject the document and vote for a more democratic, inclusive Europe.
'We in Sinn Féin oppose the Lisbon Treaty, not because we are 'Eurosceptics' but because we are ambitious for Europe, because we believe that collectively and democratically Europeans can achieve great things,' Ms McDonald said.
'We cannot support a Treaty that gives unaccountable and unelected officials greater powers, undercuts public services, commits Ireland to a common defence and reduces Ireland's voice on the EU stage.'
Martin McGuinness urged the Democratic Unionists not to break a deadline for securing policing and justice powers for the Northern Ireland Assembly just for the sake of it.
Mr McGuinness made the appeal in his first speech as Stormont Deputy First Minister.
Mr McGuinness (left) acknowledged the huge steps that have been taken by the Rev Ian Paisley's DUP since they agreed to share power with Sinn Féin and other parties in Northern Ireland in a devolved executive last May.
Dubbing Mr Paisley's party 'DUP Nua', the Mid Ulster MP urged them to stand by what they had agreed in the 2006 St Andrews negotiations.
'During the talks which led to the first meeting of the Sinn Féin and DUP leaderships on March 26 (last year), a senior member of the DUP delegation said that his party would stand by the St Andrews Agreement,' Mr McGuinness told delegates.
'People are now demanding that they do just that. The transfer of power is both logical and necessary. It is also supported by the vast majority of people from all backgrounds.
'The DUP need to approach all of this in a sensible way.
'The days of simply breaking deadlines for the sake of it has to end. The two governments (in London and in Dublin) must fulfill their commitments on this issue. They need to act and act decisively in the coming months.'
The Ard Fheis was also addressed by Raymond McCord (below), whose son was murdered by the UVF in 1997.
Wearing an Orange Order sash, Mr McCord, made history by becoming the first unionist to address a Sinn Féin Ard Fheis.
Addressing delegates, he berated the DUP leadership for failing to respond to a government report revealing police shielded a north Belfast UVF murder squad doubling as informers.
Instead, he applauded Sinn Féin for championing his cause to expose collusion between the British security forces and loyalist killers.
Later, delegates decisively rejected an attempt to remove the aim of establishing socialism from the party's constitution.
The Ard Fheis concludes tomorrow with Gerry Adams' presidential address.
RTÉ.ie Live: Watch live coverage of conference proceedings tommorrow between 11am and 12.40pm, and see Gerry Adams' leader's speech at 5pm.
