Next Sunday and Monday, 25 and 26 June, Italians will once again go to the polls, the third time in as many months for most of them. The first was for the parliamentary elections in April, then to vote for the city councils last month and now, according to former President Oscar Luigi Scalfaro the most important vote of all, on whether to uphold or strike down the constitutional amendment passed through parliament by Silvio Berlusconis centre-right coalition last November.

Most politicians, the media and, it would seem, the general public do not share Scalafaros opinion. Up till now, this has been a very low key campaign; there are few posters out on the streets, mostly peeling off the thick wads left over from the other campaigns. Both Mediaset and RAI give supposedly neutral, public information spots which have been strongly criticised by Italys most eminent political commentator, Giovanni Sartori, but there is not a lot of informed debate. The politicians too have been keeping low profiles.

But the last week promises to be much more heated, with big public meetings promised and Silvio Berlusconi at least, saying that he will use the vote as another test of the governments support. Inevitably, the centre-left parties will have to react even though the prime minister, Romano Prodi, has said that he is campaigning purely on the referendum.

The constitutional amendment has three main sections: it gives more power to regional governments (the so-called devolution); it gives more power to the prime minister and, finally, it changes the relative powers of the two chambers of parliament.

In 2001, the centre-left dominated parliament gave more powers to the regions. The centre-right never implemented those reforms but produced its own constitutional amendment last November under which the regions would get exclusive power over health, the organisation of education and local police. Both left and right have misgivings about the amendment and many fear that it would increase the differences between north and south. Lawyers worry that responsibility is not clearly divided between central government and the regions so that there would be endless wrangling. But it was this part of the amendment that was the condition for the Northern Leagues continued support of the Berlusconi government and, only last week, the Leagues leader Umberto Bossi threatened undemocratic methods if it was struck down.

As for the executive, the reform has the prime minister in practice directly elected; he does not need a vote of confidence from parliament and he takes over some of the powers now held by the president of the republic, like appointing and removing cabinet ministers and most importantly dissolving parliament. This reform would not give an Italian prime minister much more power than, say, a British one, but given the nervousness about concentration of power in Italy, the significance is very different.

The last part of the reform would radically change the relative powers of the two chambers and their size. Today Italy has perfect bicameralism, the two chambers have equal powers. With the reform, the number of deputies would go from 630 to 518 and senators from 315 to 252. The chamber would deal with national business, defence and foreign affairs while the senate would look after matters which overlap national and regional competences.

If the reform is confirmed this weekend, then the devolution measures would start being applied immediately, the changes in the prime ministers powers after 2011 and the changes in the legislature in 2016.

There are two major problems surrounding this referendum and neither can be solved in a week. The first is that the reform covers many complex issues and even now there is very little articulate debate. Some of the measures are simple and straightforward (the president has to be 40 rather than the present 50 years old); others, like devolution present major difficulties. Secondly, by its nature a referendum is a very blunt instrument. It allows only a yes or a no and voters cannot pick and choose.

Recognising this, both sides have announced that next week they will begin a serious debate on constitutional reform which everyone can agree on; but then most of them posit the future debate conditional to their own side winning the referendum.

At the moment, most of the polls give the no vote a good advantage but it went from about 20 per cent to 7-10 per cent last week and as the reforms defenders hammer away on the money saving cuts in the number of parliamentarians, the gap will narrow further.

Unlike referendums on ordinary laws, this one needs no quorum so whatever the turnout, the result will be valid. And whatever the result, this vote is just another small piece of a constitutional reform puzzle which goes back 10 years to the bicameral Commission and in some ways much further. It will not be the last word.