A democratic election to choose the next chief rabbi could be run cheaply and efficiently by the United Synagogue, according to the Electoral Reform Society.

But the organisation, Britain's leading administrator of ballots and elections, said the US must ensure the electorate is clearly defined and avoid confusion over who is eligible, or risk the legitimacy of the entire process.

Ashley Dé, ERS communications director, said: "There are no practical barriers whatsoever, and an online vote could be delivered for pennies per head.

"The fundamental question with elections is deciding what a community wants from its leader. Who can vote, how they vote, and the terms of office a winner serves, all shape the office that's being elected."

Mr Dé was reflecting on the JC campaign, launched last month, for the next chief rabbi to be elected rather than selected, with synagogue members and a wider section of the community having a say in the process.

Election experts said the community would need to consider a number of issues when setting up a process. Defining who would be able to vote, and selecting the form of the election, could prove among the most challenging aspects.

United Synagogue president Stephen Pack intends to create two selection panels to decide on an appointee by Rosh Hashanah 2012, but has not ruled out offering members a vote of some sort.

The ERS said lessons could be learnt from other religious groups in Britain and abroad. The Church of England, for example, allows dioceses to elect representatives to the General Synod by postal vote. Parish electoral roles – similar to synagogue membership lists – are used to determine who can vote. The General Synod then selects the head of the church.

The Muslim Council of Britain uses an electoral college system to elect senior members, with mosques providing different numbers of delegates to a general assembly, dependent on their size. The assembly then makes appointments.

For a chief rabbi election, an electoral roll, based on US members, could be used to select representatives for at least one of Mr Pack's proposed panels.

Alternatively, a direct election, giving all synagogue members over the age of 18 a vote on a one-person-one-vote basis would be possible. Mr Dé said such a move would be "bold" and would broaden the debate on who succeeds Lord Sacks.

He added: "Identifying your voters is key. Any election requires an electoral roll that the community can have full confidence in. Once you've agreed who's eligible to vote, everything else can follow. Getting this right is vital, whether you go for one person, one vote, or an electoral college.

"The voting system will determine not just the kind of winner you get, but the kind of campaign they have to run. Do you want a polarising figure playing to their base or a consensus builder?"

But Mr Dé said a first-past-the-post election, used to elect MPs, would not provide a suitable option for the community, as it would leave too many people feeling disenfranchised.

Instead the "alternative vote" system – rejected by the British public in May's referendum – would ensure chief rabbi candidates had to "reach out to a wider electorate and secure majority support".