The referendum on the European constitution will be supervised by Britain's elections watchdog according to a tight set of rules.
The question has to be "intelligible"
The Electoral Commission will vet the question put in the vote, although Parliament will have the final say.
And it will restrict the amount of money campaign groups are allowed to spend on trying to sway voters.
The watchdog can decide which two organisations should officially represent the two sides of the debate.
Those "designated organisations" are allowed to spend up to £5m and would be eligible for up to £600,000 each from public funds, as well as a free mail shot to every British household and referendum campaign broadcasts.
All other campaign groups or individuals spending more than £10,000 will have to register with the commission and are barred from spending more than £500,000.
Commission chairman Sam Younger, who will act as the chief counting officer in the referendum, said the criteria was still being drawn up for choosing the "designated organisations" for the referendums on regional assemblies.
On Monday, he told reporters he wanted to get experience from this autumn's regional referendums before holding a UK-wide poll.
The commission also opposes holding national referendums on the same day as party political elections, saying it could confuse voters.
Tony Blair has now announced that the vote will be on the constitution itself, rather than a wider poll on Britain's place in the European Union.
Yes or No?
Mr Younger said he did not know what the referendum question would be, adding: "It is not necessarily a yes or no response."
Some people argue such questions are biased towards the "yes" camp, but they are being used for the regional assembly referendums because campaign groups are already calling themselves "yes" and "no".
The same approach seems likely for the European referendum.
Mr Younger said the commission would publicly deliver its verdict on the question's "intelligibility" - its clarity, whether it could be understood by voters and the fairness of its phrasing.
The government and Parliament do not have to accept the commission's recommendations but would be unlikely to spurn the advice of the referendum's organisers.