Facebook has launched an "I'm a Voter" button on its newsfeed in a bid to encourage turn out at polling stations during Friday's referendums.

The “megaphone” button, which will appear on the pages of those eligible to vote, is fast becoming a feature of ballots across the globe.

It is designed to allow account holders communicate with others that they have voted and, in so doing, encourage others to follow suit.

Once pressed, the user will have the option to attach a message. It is up to the individual whether or not they wish to reveal how they voted.

The social network said the same function used during the recent UK general election saw more than three million people share that they had cast their ballot.

It has also been used in the last three US elections, an EU parliamentary election, the Scottish independence referendum and in India, where it was pressed by 4.3 million people.

Voter turnout

Citing a 2012 study in Nature magazine, Facebook said conversation on its site “ahead of an election can actually increase voter turnout”.

It said 300,000 voters turned out to participate in US elections in 2010 having seen Facebook posts from friends.

“It is hoped that by allowing Irish voters to share that they have voted, more people will be inspired to get out and vote on May 22nd,” the company said in a statement on Thursday.

Politics and government specialist at the company Ellizabeth Linder added: “Politics is one of the most talked about topics on Facebook. People come here to have meaningful conversations and to engage with leaders and organisations about issues that matter to them.”

An average Facebook user has 120 friends.

Almost 66,000 people have been added to the electoral register in the run up to Friday.