1. The Reform Treaty, as compared to the Original Constitutional Treaty, requires a referendum of the electorate of the United Kingdom because it is the equivalent to the Constitutional Treaty, even if not the same. It is a distinction without a proper difference.
2. A referendum is required for the following constitutional reasons: the Reform Treaty with the merger of the TEC, based on the Treaty of Rome (which was the genesis of the European Economic Community), followed by the Single European Act on the one hand and the TEU (with its genesis in the Maastricht Treaty which deals with European government, followed by Nice and Amsterdam), on the other, into a Union with an overarching single legal personality and a self-amending text is "substantial constitutional change", even "fundamental change" in terms that warrant a referendum according to the government's own criteria.
4. The Reform Treaty on all these tests requires a referendum. It would be a deceit of the electorate (even by the criteria for a referendum set out by the Government) to refuse to hold one, unless the Treaty itself was rejected by the Prime Minister in the IGC on 18/19 October as he should. Unless this occurs, refusal to hold a referendum would be a breach of trust with respect to the Reform Treaty (let alone past promises about the original Constitutional Treaty made in 2004) and would run clearly contrary to the assertions of the present Prime Minister that he is committed to restoring good governance, democracy and trust.
These amendments were voted down by the Labour majority. It will be interesting to see what the final report says. If the Sunday Express is right, the report (endorsed by Labour MPs) will indeed say that the Treaty is not substantially different from the original constitutionUPDATE: I have had to substantially change this post after David Boothroyd correctly pointed out that the amendments above were not voted for by Labour MPs. This was not a deliberate misrepresentation on my part; I misunderstood what was being said on the Daily Referendum blog and thought that these paragraphs were part of the main report. Apologies for any confusion.