Pope Francis has urged critical Catholic leaders to set aside internal politics and focus on making the church more welcoming, as he opened an influencial gathering of bishops that critics have claimed will “poison” the faith. Disagreement between progressive and traditional Catholic figureheads has been rife in the run up to the Synod, the global gathering of church leaders held every four years in the Vatican City. Two days before the synod started, five of the church's 242 cardinals revealed they had sent a letter to the pope calling for clarifications on the potential of blessings for same-sex couples, the role of women in the church and other issues, such as the acceptance of LGBTQ+ Catholics. These are all subjects on the table at the gathering – including aims to elevate more women to decision-making roles, including as deacons, and for ordinary Catholic faithful to have more of a say in church governance. Also under consideration are ways to better welcome those who have been marginalised by the church, and for new accountability measures to check how bishops exercise their authority to prevent abuses. While the more progressive pope has said the Church must be “open to all”, his critics have accused him of pushing for modernising changes that “risk the very identity of the church”. Both sides of the divide have accused one another of politicising the Catholic establishment. Cardinal Raymond Burke, a Rome-based American traditionalist, accused the pope on the eve of the Synod of “bringing forward an agenda that is more political and human than ecclesial and divine”. He added that the push to modernise amounted to introducing the “poison of confusion, error and division”. In an opening speech today in St Peter’s Square for the gathering, the pope reacted by calling on his critics to avoid “human strategies, political calculations or ideological battles”. “We are not here to carry out a parliamentary meeting or a plan of reformation,” he said in the homily of the Mass, which the Vatican said was attended by a crowd of 25,000. Church leaders have been preparing for the month-long synod for the past two years, asking Catholics around the world to share their vision for the future of the church. Discussions will take place throughout this month and resume next October. A papal document will follow in 2025 that could mean changes to church teaching. The pope has decided to include about 70 lay people, half of whom are women, among 365 “members” permitted to vote at the synod on catholic principles. The empowerment answered long-made calls from progressives Catholics to lend women a more influential voice in the church. Conservatives derided the move as undermining the very concept of this synod, arguing that any discussions on doctrinal issues should come from those who have been ordained. This requirement precludes female voting, as women cannot be ordained in the Catholic Church. Before the opening Mass got under way, advocates for women priests unfurled a giant purple banner reading: “Ordain Women.” The pope was also joined in celebrating Wednesday's Mass by most of the 21 new cardinals he promoted to the high rank on Saturday, a move that further cements his legacy. He has now appointed nearly three-quarters of the electors who will have the right to vote for his eventual successor. Pope Francis has also issued a stark warning on rich nations to commit to real action on the climate crisis, in an update to his landmark 2015 encyclical on the environment released ahead of the COP28 conference starting next month in Dubai,. “The world in which we live is collapsing and may be nearing the breaking point,” he said. “It is indubitable that the impact of climate change will increasingly prejudice the lives and families of many persons.” The pontiff called for an abandonment of "short-term interests of certain countries or businesses," and political forces, saying it was high time to rise to the occasion. "In this way, may they demonstrate the nobility of politics and not its shame". Reuters and Associated Press contributed to this report Read More Point of no return: Pope challenges leaders at UN talks to slow global warming before it's too late Pope will open a big Vatican meeting as battle lines are drawn on his reform project Pope Francis suggests same sex couples could receive blessings Things to know about the Vatican's big meeting on the future of the Catholic Church Clergy abuse survivors propose new 'zero tolerance' law following outcry over Vatican appointment 5 conservative cardinals challenge pope to affirm church teaching on gays and women ahead of meeting