Pope Francis, who has faced his fair share of criticism as well as support over recent years, has said that it is 'not a sin to criticise the pope'.

Speaking to Italian bishops during their general assembly, the pope revealed three 'worries' during his speech: the decline in vocations, financial scandals, and the reduction and merging of dioceses, the Catholic Herald reported.

Francis encouraged the bishops to 'speak openly' and urged them to tell him 'all the words, your concerns, criticisms – it is not a sin to criticise the Pope here, yes, not a sin – and inspirations that you carry in your hearts'.

The pope was expressing concerns over the decline of vocations to the priesthood and religious life in Italy, adding that 'God only knows' how many seminaries and monasteries will have to close.

He blamed a range of factors including demographic changes, scandals in the Church and a 'dictatorship of money' that turns young people against making life-long commitments.

The pope said that Italy is experiencing a 'crisis of vocations' in a region that was once the world's biggest source of missionaries, and was now entering a 'vocational sterility'.

He concluded: 'These are my concerns. They are points for reflection.'