The conclave to elect a successor to Pope Benedict XVI has been set to begin next Tuesday, 12 March. Most observers believe the lack of strong leading candidates suggests the process is likely to take longer than just two days, as happened in 2005 at the last papal election.

The College of Cardinals chose the conclave's starting date this afternoon at their eighth general congregation, or pre-conclave meeting, in the Vatican's Synod Hall. It is believed they will hold at least two more such gatherings, tomorrow morning and on Monday morning, before beginning the voting phase.

The top-secret congregations are being led by the college's dean, Cardinal Angelo Sodano. In 2005 the cardinals met 12 times under the leadership of the dean of the time, then-Cardinal Joseph Ratzinger.

Cardinal Sodano, the 85-year-old former Secretary of State, will conclude his role in this important process by presiding at what is considered the conclave's official opening Mass. That will take place on Tuesday morning in St Peter's Basilica and will be concelebrated by the 115 cardinal-electors who will, later that afternoon, formally process into the Sistine Chapel to hold the first round of voting for the next Bishop of Rome.

But before casting their ballots they will listen to a sermon by Maltese Cardinal Prospero Grech OSA. The Vatican said today that the 87-year-old Augustinian has been selected to preach the traditional conclave homily. Cardinal Grech has spent most of his life in Rome as a professor of ancient Christian writings (Patristics).

In the absence of a clear front-runner capable of capturing the necessary two-thirds majority, or 77 votes, to get elected, next week's conclave is most likely to produce a compromise choice. And it could be a surprise candidate who has not received much media attention up to now.

One common scenario being painted by veteran Vatican-watchers here is that the conclave process will boil down to a choice between a candidate backed by Roman Curia cardinals, and their allies, and a candidate put forward by cardinals intent on radically reforming the Curia.

Some Italian observers have surmised that Cardinals Sodano and Tarcisio Bertone - bitter rivals inside the Roman Curia for the last several years - have made a sort of non-belligerence pact to keep the non-curialists from capturing the papacy. The logic is that it would be better for the rivals to join forces and make modest reforms rather than risk allowing outsiders the chance to take more drastic action to re-order the Church's central bureaucracy.

It appears that the first bloc would be interested in seeing Cardinal Odilo Pedro Scherer, Archbishop of Sao Paulo and a former official at the Congregation for Bishops, as the next pope. He is one of only five cardinals on the commission that oversees the Institute for Works of Religion (IOR or Vatican Bank). The other bloc seems to be coalescing around Cardinal Angelo Scola, Archbishop of Milan. However, it is likely that neither will be able to get the necessary 77 votes and a compromise candidate will be elected.

Above: Cardinals George, Onaiyekan and Toppo arrive for a prayer service on Wednesday in St Peter's. Photo: CNS/Paul Haring