The conclave to elect the successor to Benedict XVI gets underway in Rome today.
Cardinal Cormac Murphy-O'Connor is inviting Catholics across England and Wales to pray for the Cardinal Electors during the secret meeting.
He was speaking in Rome from his titular church, the Basilica di Santa Maria sopra Minerva.
"Every cardinal has a church in Rome because in the early days, it was the parish priests that elected the Bishop of Rome. Every cardinal today has a church in this great city," he explained.
The cardinal said the many visitors coming to the church were not only tourists but people wanting to pray for the election of the next pope.
"These days when we're thinking about the legacy of Benedict XVI and also the cardinals who will vote for the new pope," he said.
"It's not only the cardinals who will be praying, we should pray with them. I hope all of you - especially those of you in England and Wales - will be praying for the Cardinal Electors and the Church at this time."
This afternoon, the 115 Cardinal Electors will gather in the Pauline Chapel for prayer and reflection before processing through the Sala Regia to the Sistine Chapel.
There they will take their seats to elect the 265th pope, swearing an oath to observe the rules of the conclave, which include fidelity to the election of the pope and a vow of secrecy.
The Cardinal Electors are all below the age of 80 as those older are excluded from the process.
According to the Apostolic Constitution, on the afternoon of the first day, one ballot may be held. If no one is elected, then four ballots will be held each successive day, two in the morning and two in the afternoon, until a candidate is elected.
If no result is obtained after three vote days of balloting, the process will be suspended for a day of prayer, meditation and reflection.
A two thirds majority is required for the election of a Pope.
Benedict XVI stepped down last month because he felt he no longer had the strength to meet the demands of the role.
French Cardinal Philippe Barbarin told reporters there was no obvious frontrunner going into the conclave.
He was quoted by Reuters news agency as saying: "Last time around there was a man of stature, three or four times that of any other cardinal.
"That is not the case this time around. Therefore, the choice has to be made among one, two, three, four ... a dozen candidates.
"We still don't really know anything. We will have to wait for the results of the first ballot."