Steve Baker is co-Chairman of Conservatives for Britain and is MP for Wycombe.

The upcoming referendum will be the first time that most people in the UK will have had a chance to have a say on our EU membership. If the vote goes ahead in June this year as expected, only those now over the age of 59 would have been able to cast their vote back in 1975, when we elected to stay in what was then called the European Economic Community.

However, those like myself who have kept a keen interest in the debate for many years, will know that we came close to holding a referendum on the EU in 2005. Although it was not as significant as an In/Out referendum, we were due to vote on ratifying the European Constitution. We were only denied this vote as the French and Dutch rejected the Constitution at their own plebiscites.

Not to be defeated, the EU reintroduced the Constitution in the form of the Treaty of Lisbon. Gordon Brown refused to put it to a referendum, apparently satisfied that the differences between the two were so significant that the British people did not need to be consulted. Many in my party were outraged at this affront to democracy, especially as analysis of the two documents revealed they were almost identical.

In 2008 David Cameron, as leader of the Opposition, issued a cast iron guarantee to hold a vote on the Treaty, stating ‘as soon as we have an election, the sooner we can have a referendum’. I stood shoulder to shoulder with Mr Cameron on this, as I too was concerned at the centralisation of powers to Brussels without first giving the British people a choice. I put my name to the Conservative Party European Election manifesto of 2009, which stated that ‘in our view political integration in the EU would have gone too far, the Treaty would lack democratic legitimacy, and we would not let matters rest there’.

With this in mind, I was thrilled when the Prime Minister led us to a famous electoral victory, and in doing so pledging to fundamentally reform our relationship with the EU ahead of a referendum.

However, as I have watched the renegotiation continue and the EU water down Mr Cameron’s demands, I see that none of the issues upon which I campaigned against ahead of the Lisbon Treaty are up for discussion. Indeed, a vote to remain would mean endorsing 50 specific examples of centralised powers enacted by the Lisbon Treaty, which the Conservative Party fought to oppose.

These transfers of powers were far from insignificant. They included the creation of a permanent President of the European Council, which in 2008 the Shadow Foreign Secretary William Hague described as ‘a mistake’. They also saw a High Representative for the Common Foreign and Security Policy put in place. The Conservative’s European Party Election manifesto of 2004 saw this as a clear power grab, which would give the EU ‘most of the trappings of statehood’.

A central pillar of the new arrangement was the insertion of the Charter of Fundamental Rights into the EU Treaties. At the time, Tony Blair assured us that the UK would not be bound by the Charter, but the European Court of Justice has since ruled that it applies in the UK just as it does in any other member state. Although at first sight this might appear another run of the mill ruling from Brussels, it in fact has a significant impact on our day to day lives. EU judges have used the Charter to decide whether prisoners should have the vote in the UK and to prevent us from removing foreign criminals and terrorist suspects.

But this huge transfer of power has not only had an impact on our sovereignty, it has hit the public purse hard. Some of the measures which myself and my Conservative colleagues campaigned against have proved very costly, landing the British taxpayer with a bill of over €100 million. A vote to remain in the EU is to endorse this burdensome expenditure, and who knows what the UK will be asked to pay for in future EU projects.

David Cameron’s renegotiation will go a very short way to reverse this centralisation of powers. Indeed, it might only restore national control over two out of the 50 areas in which we handed powers to Brussels. Even then, for these to take full effect requires Treaty change, which the Government has made clear it is not seeking ahead of the referendum.

The problems in the EU were evident a decade ago, and little has changed since. If we vote to stay in the EU, it is in effect an approval of the Lisbon Treaty, European Constitution and everything the Conservative Party fought tooth and nail to oppose. We were denied a vote in 2005, but today I urge my colleagues to make their voice heard and Vote Leave.