Pope Francis has by far the most clout of any world leader on Twitter because he is so widely retweeted, a study of political use of the social network showS.

With 14 million followers for the nine different language versions of his @Pontifex account, the cyber-savvy pontiff boasts just a third of those notched up by US President Barack Obama.

But that it not the key measure, said Matthias Luefkens, who steers the annual Twiplomacy survey.

“It’s not the number of followers which is really important, but the reach, the engagement,” he says on Wednesday.

The real benchmark is tweets retweeted by followers to their own network.

Pope Francis wins hands down, with his Spanish-language tweets retweeted more than 10,000 times on average and his English-language tweets, more than 6400 times.

Obama’s 2012 election victory tweet — a photograph of him embracing First Lady Michelle Obama and the words “Four more years” – was retweeted a massive 806,066 times.

But on average, @BarackObama gets 1400 retweets.

Obama’s use of social media is credited as a key factor in his landmark 2008 election.

The @BarackObama account, created in 2007, has 43.7 million followers, but is not a US presidential feed and is run by his political campaign staff.

The official @WhiteHouse account has more than 4.9 million followers, putting it fifth in the global pecking order, just behind the account of India’s new Prime Minister Narendra Modi, and Indonesia’s President Susilo Bambang Yudhoyono, who has five million.

But despite taking to Twitter with gusto, politicians are light years behind celebrities.

Top-ranked stars’ accounts include @justinbieber with 52.5 million followers, beaten by @katyperry, who has 54 million.