"[Pope] Francis created [the Secretariat] to be the tip of the spear on financial reform but it's on life support right now. If he wants to send a signal he's serious about it, he would have to bring in new leadership.

"And George Pell is genuinely committed to financial reform in the Vatican, so I think he would be the first to acknowledge this."

On Tuesday, the Vatican issued a short statement saying the Holy See had "taken note" of the decision to commit Pell to trial.

"Last year, the Holy Father granted Cardinal Pell a leave of absence so he could defend himself from the accusations," the statement said. "The leave of absence is still in place."

Andrea Tornielli, editor of the Vatican Insider website for La Stampa in Rome, said the statement suggested that "from the point of view of the Pope nothing has changed" with Pell’s committal.

"It’s difficult to predict," he said. "I don’t know if in the next few months the Pope will take a decision [to choose a new prefect to head the Secretariat].

"The solution could come from Pell. Maybe he could ask the Pope, ‘please accept my resignation and you can appoint a new prefect… because now I have to defend myself in front of a court and it will take too much time, it will be impossible for me to return to Rome in the next one or two years'."

But, he added, "it is delicate".

Another well-connected Vatican observer, the National Catholic Register’s Ed Pentin, said the "old guard" at the Vatican would be pleased with the committal.

"The longer Cardinal Pell is away from Rome the more likely it is that the financial misconduct of the 'old guard' will continue, and the finance reforms Pell was working on further stalled or reversed," Pentin said.

"They wanted Pell out and succeeded."

He said the "old guard" may push for the status quo to continue.

"No-one at the helm means they can continue reversing the reforms, and that only needs to continue for another year or so by which time Pell’s mandate will have come to an end," he said.

Bishops are required to submit their resignations to the Pope at age 75 but the Pope can choose to accept it much later. Pell turns 77 in June.

Should he be found not guilty, he may still wield considerable influence in Rome.

He would probably stay on the ‘C9’ council of cardinals that are Pope Francis’ closest advisers, Allen said.

Allen said the Pope "has proven to be pretty stubborn when his friends are under fire", and the Vatican would be careful not to say anything about the case or draw any inferences until there was a finding of innocence or guilt.

"[Pell] continues to enjoy real respect in Rome, though frankly we have to see what evidence emerges at trial," he said.

"Most people in the Catholic church see George Pell as a point of reference, especially for English speaking Catholicism, for the better part of three decades.

"If he is cleared and no longer under the shadow of charges you could easily see him at least informally play a role as advisor for senior people [at the Vatican] including the Pope."