Updated

Pope Francis' top advisers are coming to his defense amid an unprecedented wave of conservative criticism that represents the biggest challenge to his mercy-over-morals papacy.

In an unusual gesture, the nine cardinals from around the world who advise Francis on running the church made a public show of support this week after posters featuring a scowling Francis appeared around Rome.

The posters referenced some moves perceived as heavy-handed and asked, "Where's your mercy?"

The Vatican also published a book by the Holy See's top canon lawyer on Tuesday fully endorsing Francis' controversial opening to divorced and civilly remarried Catholics — the main bone of contention between the pope and traditionalist Catholics.

The book's author, Cardinal Francesco Coccopalmerio, said in an interview: "He knows we love him and we are with him."