By Andrew Cawthorne and Diego Ore CARACAS (Reuters) – Venezuela’s government formally invited Vatican No. 2 Cardinal Pietro Parolin on Wednesday to mediate talks with the opposition in hopes of stemming violence that has killed dozens in the nation’s worst unrest in a decade. In a letter, President Nicolas Maduro’s government asked that Parolin, a former envoy to Venezuela who is now the Vatican’s secretary of state, be named a “good faith witness” to a dialogue agreed after two months of protests. A Vatican spokesman confirmed the Roman Catholic Church’s willingness to mediate, but gave no details. Venezuela’s opposition coalition had indicated that current Vatican envoy, Aldo Giordano, would be attending the first formal talks, which are to start on Thursday in Caracas.