My Lords, Britain’s relationship with the European Union has been an issue of political tension since we joined the Common Market, as it was then known, in 1973. The reason for this is simple: that our relationship with the European Union is of immense importance. It is not just the large amounts of money that the European Union spends. It is not just the enormous amount of trade that occurs within the European single market. It is, fundamentally, that we are engaged with our European partners in a unique sharing of sovereignty. It is this question of how to share sovereignty between national Governments and the European Union, and the exercise of power that flows from this, that has led to the furious political debate on Europe over several decades.The latest form of this debate is the consideration of the proposed treaty of Lisbon, also known as the reform treaty. I fully support my party’s proposal for a referendum on the reform treaty. There is a moral obligation for this in that the Conservative Party fought the last general election on a promise of holding a referendum on the EU constitutional treaty. Although the question of how different the EU constitutional treaty and the reform treaty are has generated a great deal of debate, I am confident that the reform treaty is largely the same as the constitutional treaty. I come to this conclusion with the support of the European Scrutiny Committee of the other place, which has described the reform treaty as “substantially” the same as the European Union constitution. Let us not forget that that committee has a Labour majority and not a Conservative one.Beyond the moral obligation of honouring an election pledge, I believe that it is important that the public have a vote on the reform treaty because of the ever growing divide between the British electorate and European politics. One indication of that was the turnout at the European parliamentary elections in 2004, when only 39 per cent of people voted. In other words, six out of a possible 10 voters ignored that election. A public vote on the reform treaty would be a once-in-a-generation chance for our relationship with the European Union to take centre stage in public life, just as occurred in 1975 over whether we would remain part of the then Common Market. It would be a great opportunity for those opposed to surrendering further powers to Europe to make the case against to those who sincerely believe that giving extra powers to the EU institutions is in Britain’s national interest.A number of politicians hold the honourable belief that we live in a parliamentary system and that we should therefore not need to resort to referendums. The problem with this argument is that, since the 1975 referendum, referendums have become part of our political process in regard to constitutional change. There were referendums on Welsh and Scottish devolution in 1979 and 1997. Every local council has the right to call a referendum if it wishes to introduce a directly elected mayor. So while I respect those that make this argument, British constitutional practice has moved beyond it. A debate of this nature could actually be civilised, and a much greater understanding of, and engagement with, the question of Europe by the British public will occur. Of course there will be voices in the debate which prefer to criticise our views, but that is the nature of an open and robust democracy. I have more than enough confidence that voters will see through this and get to the substance of the issue; namely, the balance of power between Westminster and Brussels.The final question that people ask is: what would happen if Britain voted no in a referendum? Many of those in favour of the treaty suggest that there could be a doomsday scenario, where Britain would be forced by all the other countries of the European Union to face a stark choice: either ratify the treaty or leave the Union. The problem with this argument is that it is not supported by the practice of the European Union. When Denmark voted against the Maastricht Treaty in 1992, it did not lead to such a choice. Rather, it led to a further negotiation which produced the Edinburgh agreement, which gave the Danes a number of exceptions. In an irony of history, the Danish Prime Minister has promised that he will ask the Danish people to give up these exceptions in a referendum in the near future.Not only must we trust the British people in a vote on this issue, but we must have the confidence to engage with the electorate and abide by their decision. If they vote against the treaty, the Government and politicians must deal with that and go back to our European neighbours and renegotiate. On the other hand, if the result of the referendum is to support the treaty, those who are opposed to it must acknowledge the will of the people and accept that the treaty in its current form will be ratified and move on.In conclusion, my greatest fear is that, without a referendum, the gap between voters and politicians over Europe will only grow. It will not be good for a semi-detached electorate to have more decisions that affect their lives made in Brussels without the debate of a referendum and the endorsement of a positive vote in favour of the treaty. In the long run, no sensible person wants this disengagement to occur because it will contribute to an even wider political disengagement, undermining the legitimacy not only of the European Union and its institutions but, to some extent, politics in this country.