The son of a socialist truck driver and a pious housewife mother, Milan archbishop Angelo Scola is the leading Italian candidate to succeed Benedict XVI and an advocate of dialogue with Islam.

The 71-year-old Scola is perhaps along with Canadian Marc Ouellet one of the closest ideological heirs to Benedict, combining conservative doctrinal views with progressive social advocacy on issues like immigration and poverty.

Scola was a favourite last time around in 2005 but was seen as too young.

This time he is clearly a frontrunner and he is not associated with the Vatican bureaucracy, whose image has been badly tarnished by infighting between Italian cardinals.

For 10 years he served as the patriarch of Venice, which gave the Catholic Church three popes in the last century, and Scola now heads up Europe's largest diocese, Milan, which has also been a major jumping off point for future popes.

He has been an important voice in the Church in condemning Islamophobia and calling for Catholics to build ties with Muslims, particularly in Europe.

Scola is the founder of a multi-lingual magazine called Oasis aimed at Christians living in Muslim countries -- a key concern for Benedict -- and has said he wants "ties of understanding and friendship with the Muslim world".

The theologian archbishop may well be one of the most internationally-minded of Italy's 28 "cardinal electors" who will be taking part in the conclave -- by far the highest proportion for any country among the 115 electors.

Scola made a name for himself as one of the brightest minds in the Italian church with his theological scholarship, his past experience as head of Rome's Lateran University and his writings on cultural and ethical issues.

He has a strong character -- critics would say authoritarian -- and is seen as dry and media-shy, traits that some would liken to Benedict, the German-born Joseph Ratzinger.

He is from the same theological school as Ratzinger, combining enthusiasm over the reformist Second Vatican Council of the 1960s with an iron-willed conviction of the need for continuity with Catholic tradition.

The motto he has adopted as cardinal is: "Your Grace is Enough".

Despite a degree of openness, Scola is no liberal on doctrine and has been close to conservative groups such as Communion and Liberation.

After a leading member of Communion and Liberation, Silvio Berlusconi ally and Lombardy governor Roberto Formigoni, was accused of sleaze and corruption, Scola was quick to distance himself from the deeply politicized movement.

Critics say that his reputation is also tarnished because he once gave philosophy and ethics lessons to Berlusconi in the 1970s, before the irrepressible billionaire tycoon entered politics at the start of the 1990s.

Scola has ruled out any easing the Church's stance against artificial means of contraception or gay marriage and has been critical of secular governments like France saying they passed laws to become "the dominant culture".

Last year, he organised an international conference of Catholic families which decided that traditional family values were "non-negotiable".

Born near Milan, Scola was taciturn and determined as a young man and once swam across the icy waters of Lake Como in the middle of winter.

He was ordained a priest in 1970 at the age of 29 and became friends with three other prelates now seen as possible successors to Benedict: Christoph Schoenborn from Austria, Marc Ouellet from Canada and Peter Erdo from Hungary.

Scola sprang to Benedict's defence when the then pope came under heavy criticism for failing to do enough to investigation allegations of paedophile sex crimes by priests, saying this was an "unjust humiliation".

Italian cardinals are not united behind his possible bid for the papacy.

Scola is seen as having engineered a conservative turnaround in Milan where his predecessors Carlo Maria Martini and Dionigi Tettamanzi were seen as progressives who were more in favour of a socially-engaged Catholicism.