Francis,
78, has said before that he would be ready to resign instead of ruling
for life if he felt he could not continue running the 1.2billion-member
Church for health or other reasons.
'Let's
be clear. The only one who cannot be substituted in the Church is the
Holy Spirit,' the Argentinian-born pontiff told 30,000 people at a rally
of Christians at the Vatican today.
He added: 'There should be a time limit to positions [in the Church], which in reality are positions of service.'
Making
clear his comments were not confined to the clergy, Francis added: 'It
is convenient that all [positions] in the Church should have a time
limit.
'There are no leaders for life in the Church. This occurs in some countries where a dictatorship exists.'
In February 2013, Francis's predecessor Pope Benedict XVI became the first pontiff to resign in 600 years.
In
an interview with Mexican television last March, Francis said what
Benedict did 'should not be considered an exception, but an
institution'.
But in the same interview he said he did not like the idea of an automatic retirement age for popes, for example at 80.