A booklet explaining the system and poll will be sent out in the run-up to the planned vote next May. The activity will be supported by a television and press campaign.
The referendum will offer voters a choice of keeping the first past the post system or switching to the alternative vote method, which ranks candidates in order of preference.
The vote was pledged as part of the Conservative-Liberal Democrat coalition agreement. It is opposed by the Tories but backed by the Lib Dems.
The Electoral Commission says that campaign funding is approved by Parliament and not Government.
It is therefore not covered by the current a freeze on “non-essential” marketing and advertising spending by government departments. Departmental spending over £25,000 now has to pass strict criteria to be cleared by the Cabinet Office.
Some Tory MPs have criticised the amount of money that will be spent on the referendum.
A Cabinet Office spokesperson says: “The referendum will, for the first time, give people a choice on the voting system they use to elect their MPs. It is clearly important that voters are provided with the necessary information to help them make an informed choice.”