During proceedings, Mark Francois, the shadow Europe minister, moved an amendment which would put a "referendum lock" on any future handover of power to Brussels – in other words making any future Treaty which transfers power to Brussels subject to a vote of the British people.
As he explained:
"These amendments and new clause 68 would ensure that any future treaty that transferred areas of power or competences from the United Kingdom Parliament to the European Union would require the consent of the British people in a referendum as a condition of its ratification. This referendum lock would give the British people the final say on whether they wish this Parliament to hand over further areas of power to the European Union. This is a right similar to the one that voters of the Republic of Ireland already enjoy under their constitution."
"If we were not to succeed tonight and if we were victorious at the general election, we would amend the legislation as an incoming Conservative Government in order to achieve a referendum lock… My party believes that the British people should be given the last word on any future transfers of power from the UK to the EU, so I challenge the Labour party and the Liberal Democrats to have equal trust in the British people and to support this amendment tonight.
"Before they vote, I would also ask them to consider the following. If they vote against the amendment, they will be voting against giving the British people a say on any future handover of power to the EU and people will rightly ask why. Their most likely conclusion will be that Labour and the Liberal Democrats, once again, mean to sign new treaties handing powers over from Britain to the European Union without consulting the voters, as they have conspired to do in the past. If that is what they plan to do, we will be happy to inform voters of their intentions at the imminent general election."
Despite the support of the SNP, several unionist MPs from Northern Ireland and a handful of Labour and Lib Dem rebels, the amendment failed by 303 votes to 183, with Labour and the Lib Dems whipped to vote against it.
The Lib Dem opposition to the amendment marks another high point in hypocrisy for them and, in particular, their leader. At the Liberal Democrat Conference in 2005, one Nick Clegg proposed a motion stating that "Any proposals which involve significant change in the relationship between the Union, the member states and its citizens should be approved in Britain through a referendum".