the case for the referendum rests above all on the need for the House and the Government to honour commitments solemnly given. How many times have each of us in the House toured schools and colleges saying to young people that they should take an interest in politics, that their vote makes a difference, and that what is said at election time really counts? What are we to say to them in future—that the fact that they elected an entire House of Commons committed to a referendum was of no account, that the Government regarded that commitment as a technicality to be escaped from rather than a promise to be kept, and that the promises made at election time do not really matter at all?
The time for debating the merits of a referendum was before the printing of each party's 2005 manifestos. Given that every MP of all three major parties were elected on that basis, the argument today is not "should there be a referendum?", but "should political parties honour their manifesto commitments?".
On another point, They Work For You really is a great website.