(Worshippers attend a prayer in an evangelical church in Leon March 11, 2012. REUTERS/Edgard Garrido )

Worshippers jumping about in church, waving their hands to the swell of keyboards and electric guitars is not a sight any pope would hope to find in Mexico, for long one of the world’s most devout Roman Catholic countries.

But when Pope Benedict visits the city of Leon in Mexico’s Catholic heartland this weekend, the growing strength of Protestant groups will be on view just hundreds of meters from where he will meet with bishops and the Catholic faithful.

The leader of the world’s 1.2 billion Catholics arrives in Mexico to find a Church struggling to keep its flock.

Over the last decade, the number of Catholics leaving the fold has posted its biggest surge in modern Mexican history as more and more put their faith in evangelical Protestantism or the book of Mormon, or turn away from religion altogether.