The Pope has ordered his senior clerical staff in Rome to employ more women, lay people and people from ethnic minorities.

This was not a mere "facelift" aimed at removing wrinkles, he told his audience of ordained men that make up the Roman Curia, but part of a wholesale "purification" of the Vatican.

"Dear brothers and sisters, it isn't wrinkles we need to worry about in the Church, but blemishes," Francis said in an unusually hard-hitting annual Christmas greeting to the Curia. 

Permanent deacons and lay Catholics must be selected to serve the Church on the basis of their spiritual and moral life and their professional competence, he said.

The lay faithful can sometimes even "be more competent than clerics or consecrated persons," he added.

"Also of great importance is an enhanced role for women and lay people in the life of the Church and their integration into roles of leadership." This should be done with "particular attention" to multiculturalism," he said.

Pope Francis chose as his theme for the annual address a celebration for the reforms he has begun in the Vatican.

The aim of reform is not aesthetic, an effort to improve the looks of the Curia, he said. "Nor can it be understood as a sort of facelift, using make-up and cosmetics to embellish its aging body, nor even as an operation of plastic surgery to take away its wrinkles."

Reform will be effective only if it is carried out with men and women who are renewed and not simply new, he said.

"We cannot be content simply with changing personnel, but need to encourage spiritual, human and professional renewal among the members of the Curia."

What the Catholic Church needs is "conversion and purification", he added. "Without a change of mentality, efforts at practical improvement will be in vain."