On his final day in office, Pope Benedict has promised his unconditional reverence for and obedience to whoever emerges as his successor, writes Religious and Social Affairs Correspondent Joe Little.

He told almost 145 cardinals in the Vatican this morning that he prayed that God would guide them as they set about electing a new Pontiff.

Cardinals Seán Brady and Desmond Connell were among those who met Benedict for brief conversations in the Apostolic Palace.

One of Pope Benedict's spokesmen, Fr Tom Rosica, told journalists he was surprised when the Pontiff addressed the 145 cardinals before greeting each one of them personally as planned.

Seated in the Clementine Hall in the Apostolic Palace, where prelates traditionally wake dead popes, Benedict listened as the Dean of the College of Cardinals, Angelo Sodano, spoke of the heart of each prelate burning inside them with love as they followed his final day in office.

Then the Pope told the men who are deemed his closest advisors he was asking God to guide them in prayer as they as they choose his successor.

He pledged his unconditional reverence for and obedience to whoever emerges to succeed him.

He is the first pope to resign willingly in eight centuries, so his reassurances of loyalty will be weighed carefully by Catholics who are entering uncharted waters.

Many observers believe the explicit vow of loyalty will allay fears that Benedict could mar his successor's pontificate when living close to him in a renovated convent in the Vatican from April onwards.

There is concern that he has chosen to continue to be called "His Holiness Benedict XVI" and "Pope Emeritus" and to wear some of the white robes synonymous with the papal office.

Earlier this month he addressed those concerns by promising to live a life of prayer and meditation hidden from public view.

But he has also said he will be available to give spiritual advice to his successor.

His outgoing personal secretary, Archbishop Georg Ganschwein, will become prefect of the new pope's household.

In today's address, Benedict also urged the cardinals to be united during the election process.

"May the College of Cardinals work like an orchestra, where diversity - an expression of the universal church - always works toward a higher and harmonious agreement," he said.

Internal division and allegations of corruption have gripped Benedict's Pontificate, particularly during the past year.

Striking evidence of the crisis was revealed in documents that his butler, Paolo Gabrielle, took from his desk and leaked to a journalist.

The affair led Benedict to commission three senior cardinals to report on the malaise in his administration.

The report will be near the top of the incoming pontiff's in-tray.

So today's parting Benedictine image of harmony will resonate with Catholics who wish for a reformed administration in the Vatican's departments of state known as the Curia.

It is expected that the world's 208 Cardinals will be formally summoned to the Vatican tomorrow.

All are entitled to attend daily meetings on the state of the Church called General Congregations.

However, only 117 are under the age of 80, after which point cardinals become ineligible to vote.

Two have asked to be excused from fulfilling their obligation to vote - an Indonesian who is too ill to travel, and Cardinal Keith O'Brien of St Andrews and Edinburgh, who resigned earlier this week in the wake of allegations - that he denies - of inappropriate behaviour with three current and one former priest in his diocese.

The Co Antrim-born cardinal says he is staying away to avoid distracting media attention from Benedict and his successor.

Church law says that the Cardinals run the 1.2 billion-strong global Christian community during the interregnum from 7pm Irish time, when Pope Benedict’s resignation takes effect.

Vatican spokesman Fr Tom Rosica told RTÉ News that he believes the first of their Congregations will assemble next Monday or Tuesday and for three more days thereafter.

One of the first items for the cardinals of all ages to decide is when the 115 younger men should lock themselves away from the world to cast a series of ballots for a new pope.

The process is called Conclave, drawing on the Latin words "cum" meaning "with" and "clave”, meaning "key".

If Fr Rosica is correct, the next Conclave could begin as soon as Friday 8 March.

The voting will take place in the Sistine Chapel beside St Peter's Basilica.

The cardinals gather in prayer under Michelangelo’s The Last Judgement and then vote.

On their first afternoon they cast one ballot each. They vote twice each morning and evening after that. The voting ends when one of their number emerges with a two-thirds majority of the votes cast.

Strictly speaking, there are no candidates and formal campaigning is frowned upon as the Holy Spirit is credited with inspiring the cardinals' choice.

But discreet and not-so-subtle soundings have been taking place for as long as two years, according to Vaticanista Tom Heneghan of Reuters.

With liberal and conservative cardinals calling for reform of the Rome Curia, there will be resistance to any effort by the influential corps of Curial cardinals rushing their brother-electors into choosing a man.

Most of the men in red who have spoken on the matter to date have indicated they want a Pope who will be able to negotiate the "storm-tossed seas and strong headwinds" which, Pope Benedict said yesterday, hindered his eight-year Pontificate.