Cardinals of the Roman Catholic church will enter the Sistine chapel on Tuesday afternoon to begin the conclave that will elect the 266th pope, the Vatican has announced.

Roman Catholic cardinals will enter Sistine chapel on afternoon of Tuesday 12 March to begin process of electing 226th pope

Eight days after Benedict XVI became the first pontiff in nearly 600 years to abdicate, a decision that stunned even his closest advisers and sent shockwaves through the world's 1.2 billion Catholics, Vatican spokesman Federico Lombardi said the process of choosing his successor would start on Tuesday afternoon after a morning mass in St Peter's basilica.

The announcement comes after five days of discussions between most of the world's cardinals aimed at establishing who among them is best suited to the job. A total of 115 red-capped prelates under the age of 80 will take part in the election.

In six sessions of formal meetings known as general congregations, the so-called princes of the church have raised wide ranging issues, including the governance of the church, its central administration or curia, and the Vatileaks scandal that dominated Benedict's last year of papacy. During that time they have also been holding informal meetings over lunch, coffee and dinner that observers say are where many of the most important conversations are had.

There is no obvious frontrunner. In an interview earlier this week with the Italian daily La Stampa, the American cardinal Donald Wuerl said the relative openness of the pool of candidates could result in a conclave that lasts longer than the last one, in 2005, which was over in two days. "There doesn't seem to be a cardinal going into the conclave that everybody says is clearly going to be the pope," he told the paper's Vatican Insider website. "Of course they often say, he who enters as pope comes out as cardinal. So I think it is going to take a little while. How little or how long, that's all in the hands of God."

According to several reports in the Italian press on Friday, however, the field of candidates has narrowed, with two leading papabili gaining the support of two significant blocks. Angelo Scola, the archbishop of Milan and a known favourite of the emeritus pope, was reported to be the candidate of those who want to see big changes in the way the Roman curia is run, while Odilo Pedro Scherer, the archbishop of São Paulo, is tipped as the choice of those within the curia.

But observers stress that, once the cardinals enter the Sistine chapel and are left there, almost anything could happen. In 1978, Polish prelate Karol Józef Wojtyla was a relative outsider until he emerged from the conclave John Paul II.

© 2013 Guardian News and Media