The convention proposes fundamental changes in Britain's relationship with Europe.

Up until this point, Britain has conceded powers to Europe to exercise on its behalf.

Mr Field believes it is time for a referendum

If the constitution goes through unamended, Europe will become a legal entity in its own right; and that new legal entity may force member states to comply with EU policy.

The draft constitution lays down that foreign affairs, security and defence can be one area where individual countries lose sovereignty.

Similarly, the new European state which will come into being will control important aspects of member countries' policies on economic and employment matters.

These are most fundamental changes and they should be put to the British people.

It may be that voters in Britain wish to agree these changes, but it must be up to them to make that change and not to have such fundamental changes forced upon them by government.

Although the government is now resolute against a referendum, a referendum there will be.

Either the government can concede that referendum, or a referendum will be organised unofficially in the country.

An alternative would be for one of the opposition parties to promise that, if elected at the next election, the only issue to be dealt with by the new parliament would be the rejection of the new constitution; and that, if once that legislation is through parliament, a new general election would be called for politicians to be elected, to operate the normal day-to-day politics of Britain.

Chris Bryant

Calls for a referendum are premature, misguided and wrong.

Premature, because we are only half way through the process and the document that has been published is only a draft.

We still have several council meetings, an inter-governmental conference and at least six months or a year of negotiations to go, at the end of which Britain will have the right to veto anything that it cannot support.

Mr Bryant says calls for a referendum are 'premature, misguided and wrong'

Misguided, because this is not the massive assault on the British way of life that the obsessed eurosceptics think.

National referendums should be used when there are matters of real national (rather than just local or regional) constitutional significance to be decided, like joining the euro.

The draft new treaty is nowhere near as significant as the Maastricht Treaty, which set up the euro - and the Tories never gave us a referendum on that.

And wrong because it would undermine Parliament.

Each country in Europe has a different way of dealing with treaties. Ireland always has a referendum. But more than half of Europe will not have a referendum, including Germany, Belgium and Greece.

I prefer the traditional British system of agreeing treaties after informed parliamentary debate.

I am proud that Labour wants to work constructively with Europe and I would be happy to fight any election on that platform.