Tartaglia was appointed the fourth Bishop of Paisley on 13 September 2005. The see had been vacant since October of the previous year, when
John Mone retired after sixteen years. He was
consecrated bishop on 20 November 2005, at
St Mirin's Cathedral in
Paisley.
Mario Conti, the
Archbishop of Glasgow, served as the principal consecrator, with
Raymond Leo Burke and Mone being co-consecrators. Tartaglia attacked UK law relating to the family in 2006. He outlined his opinion that the
Family Law Act 1996 – which made
divorce quicker and easier –
civil partnership legislation giving homosexual relationships legal status, and the
Gender Recognition Act – which allowed people to change their gender designation – would undermine the family in society. He stated, "Unfortunately, in our times, the minds of many have been so darkened by hubris and by the selfish pursuit of their own gratification that they have lost sight of the natural law which God has written into his creation...". He reiterated this stance in 2010, when he wrote to
David Cameron to insist that "the Catholic Church will not register civil partnerships nor celebrate same-sex unions: not now, not in the future, not ever, no matter what legislation or regulations your government enacts or endorses." He also criticised the UK government's decision to upgrade its
nuclear weapons capability. As president of the National Communications Commission of the Bishops' Conference of Scotland, Tartaglia wrote to every parish in Scotland in May 2008, decrying the media for pushing a "secular and humanistic agenda". Arguing his belief that "over two-thirds" of Scots are actually Christians, and that the proportion of people who work in the media does not reflect this, he wrote that this led to a "fundamental disconnection between the provider and the consumer". He received the
pallium from
Pope Francis at a Mass in
St. Peter's Basilica on 29 June 2013. Pope Benedict XVI appointed Tartaglia as the
apostolic administrator of the
Archdiocese of Saint Andrews and Edinburgh on 27 February 2013, holding the post until
Leo Cushley was enthroned on 21 September 2013 as
Archbishop of Saint Andrews and Edinburgh. Tartaglia died on 13 January 2021, two days after his 70th birthday. He had been
self-isolating at his home in Glasgow after testing positive for
COVID-19 in late December 2020 during the
COVID-19 pandemic in the United Kingdom. ==Views==