The UK government has insisted the EU treaty is not dead
The Conservatives have called on the government to allow the British people to vote on the EU Treaty after it was rejected by Irish voters.
It comes after the government said it would press ahead with its ratification of the Lisbon Treaty despite the Irish voting "no" in a referendum.
Shadow foreign secretary William Hague said the poll had "blown a big hole" in the government's European strategy.
But Labour's Harriet Harman said the treaty protected Britain's interests.
The British government says the Bill to ratify the treaty will continue its progression through Parliament - despite 53.4% of Irish voters rejecting it in the referendum vote.
The House of Lords is due to hold the third reading of the Bill on 18 June.
'Protect Britain's interests'
Ms Harman, the party's deputy leader, said: "We're not ignoring concerns, but... we have to make sure we protect Britain's interests...
"....at a time when there's problems about food supply, problems about fuel costs, problems internationally in the financial market - that is not a time to turn our back on our European partners.
"That is a time to work even more closely together."
But William Hague said the "centralising project" should be abandoned.
"The people of France, the people of Holland voted against a very similar document, the EU constitution," he said.
"Now the people of Ireland have voted against this.
"It is time to turn away from this whole centralising project and concentrate on things that really matter, of global poverty, global warming, global competitiveness, that Europe should be dealing with.
"The only point in going ahead and ratifying it would be to try to bully the Irish into voting a second time.
"I don't think the Irish should have to vote twice, when the people of Britain haven't been able to vote once."
Ireland was the only member state to hold a public vote on the treaty, which must be ratified by all 27 countries.
Europe minister Jim Murphy said it was now up to the Irish government to come up with proposals to salvage the treaty following its referendum defeat.
But he insisted the treaty was not yet dead.
"Only those who previously wished to dance on the grave of this treaty, even before the Irish referendum, are declaring it dead," he told the BBC's Today programme.
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