Saint Peter's Square
A packed Saint Peter\'s Square at the Vatican where Pope Benedict XVI holds his last general audience (Reuters)

Pilgrims have started pouring into St Peter's Square at the Vatican to witness Pope Benedict XVI's final papal address on the eve of his resignation.

Nearly 200,000 people are expected to attend the event, which usually takes place inside the Vatican but has now been moved outdoors because of the huge number of people expected to attend.

More than 50,000 ticket requests have already been made.

This will be one of Joseph Ratzinger's last public appearances as pope, and there will be no traditional kissing of the hand.

"He doesn't want to favour one or other of the pilgrims," Vatican spokesman Federico Lombardi told AFP.

The 85-year-old pontiff who decided to step down due to his health condition will be known as "pope emeritus" after the resignation. Ratzinger will also retain the title of "His Holiness" even after the abdication.

He will continue to wear the unique white cassock without any cape, confirmed the Vatican.

Ratzinger will become the first pope to abdicate his title in nearly 600 years when he ends his papacy at 20:00 local time (19:00 GMT) on 28 February.

The presence of two popes, one reigning and the other retired, is likely to cause concern in the Vatican, according to critics.

Swiss theologian Hans Kueng told the German Der Spiegel magazine earlier: "With Benedict XVI, there is a risk of a shadow pope who has abdicated but can still indirectly exert influence. No priest likes it if his predecessor sits next to the rectory and watches everything he does. And even for the bishop of Rome, it is not pleasant if his predecessor constantly has an eye on him."

Vatican officials dismiss such views. "According to the evolution of Catholic doctrine and mentality, there is only one pope. Clearly it's a new situation, but I don't think there will be problems," the editor of the Vatican newspaper L'Osservatore Romano, Giovanni Maria Vian, said in an interview.

The pope's successor will be chosen by the College of Cardinals, who will begin the process on 4 March. In all, 115 Cardinals under the age of 80 will cast their votes during the secret selection which will be held in the Vatican's Sistine Chapel.