Italy's press were writing off Prime Minister Silvio Berlusconi Saturday, with even pro-government newspapers admitting his situation looked desperate after a humiliating Group of 20 summit and the latest sell-off of Italy's bonds.

With reports of numerous defections from his ruling coalition, Berlusconi could fall at any time -- perhaps as soon as a key vote in parliament Tuesday. But, with no obvious alternative majority, what follows remains highly uncertain.

Italy's loss of credibility was a recurring theme in the press, following news that the International Monetary Fund will visit Rome quarterly to check up on its reform pledges, and a rise in bond yields to a record high Friday.

It is rare to hear a global summit talking about a country's loss of credibility and it is sad to see that this is what is happening to Italy, wrote the business daily Il Sole 24 Ore under the headline: On the edge of the abyss.

Berlusconi must now try to put the public humiliation of the G20 behind him and stem a parliamentary revolt that threatens to bring down his government Tuesday.

The daily Corriere della Sera said the latest defections took him clearly below the 316 votes needed for an absolute majority in the Chamber of Deputies and it was possible he would muster as few as 306, meaning certain defeat.

However, the situation remains fluid -- Berlusconi has a knack of bringing waverers back to the fold at the last minute.

The Judases are scared headlined the fanatically pro-Berlusconi daily Il Giornale, owned by his brother, above an article saying a group of deputies who had threatened to defect to the opposition were already having second thoughts.

DEFECTORS

Berlusconi said Friday that defectors would be betraying both the government and the country and he was confident that the vote, to formally ratify public accounts for 2010, would show he still had a majority.

If Berlusconi is ousted it will probably provide some respite for Italian assets on financial markets, but it will certainly not be the end of Italy's problems, and will probably usher in a spell of intense uncertainty.

Markets would like to see the media tycoon replaced with an unelected government of experts to pass unpopular structural reforms ahead of the next election, scheduled for 2013, yet many commentators doubt this could muster a majority in parliament.

Polls suggest that a snap election would be won by the centre-left opposition. But even here, there is little prospect of decisive government from a broad grouping of parties with no obvious leader or any consensus on the policies needed to get Italy out of its crisis.

Anti-Berlusconi newspapers Saturday reiterated their frequent calls for him to quit, but the middle-of-the-road daily La Stampa also said he should go for the good of the country, his own coalition and his voters.

With every day that passes, our premier makes it more clear that he has lost touch not only with Italy but also with reality, the paper's director said in an editorial.

Berlusconi was widely panned for playing down the impact of the debt crisis on ordinary Italians and saying the attack on Italy's bonds was a passing fashion.

A tense joint press conference at the end of the G20 summit also laid bare the strain in his relations with Economy Minister Giulio Tremonti, who declined to directly deny that he believed his boss should stand down.

Even the pro-government daily Il Foglio, directed by one of Berlusconi's advisers, called him a shadow of himself and said Italy was an extremely solid country but we lack one detail: political leadership.

(Editing by Kevin Liffey)