In a bid to secure the passage of Italy’s hotly debated same-sex unions law, the Italian prime minister has called on his own Democratic Party (PD) to reach out to allies in the political centre.

Italy, the last Western European nation with no laws on same-sex partnerships, falls behind other Catholic-oriented nations such as Ireland, which last year voted for same-sex marriages in a public referendum. Both its own constitutional court and the European Court of Human Rights have urged the country to consider its own same-sex unions bill, but public opinion in the nation remains split, influenced in no small part by the presence of the Roman Catholic church in its culture.

The PD, who had formerly counted on support from at least one of its opposition parties, has accused the Five Star Movement (M5S) of trying to sabotage the bill. Although M5S had previously seemed supportive, the party blocked a ‘kangaroo’ motion that would have allowed the bill to ‘leap over’ any further instructions, after the PD included a reform that would grant limited adoption rights to same-sex couples.

Last week, when the M5S blocked the PD proposal to fast-track the Senate’s voting on the law, it opened the bill up to thousands of expected amendments and reforms from opposition parties, which could potentially delay the bill indefinitely.

‘On civil unions, we are at a crossroads,’ Prime Minister Matteo Renzi said at a recent party meeting in Rome.

Renzi suggested that, to avoid further unanticipated blocks by M5S, the PD should ‘try out a government [coalition] agreement’ on the reform by making concessions to centrist parties.

If such concessions were made, the government would be able to force the bill through the Senate by calling for a vote of confidence. Although the coalition would have a slim majority, such a measure could result in the prime minister resigning if he loses the vote, and the concessions could harm the reform to allow stepchild adoptions.

The PD’s centrist allies have previously called for a drop to the proposed stepchild adoptions provisions, which remain the most controversial part of the bill, since they enshrine in law the idea of same-sex-led family unions at odds with the biblical interpretation of families as led by a man and a woman.

These provisions would allow same-sex partners to adopt each other’s children to provide further legal protections for LGBT families, and prevent same-sex-led family units being torn apart by death or incapacitation of a biological parent.

LGBT campaigners see the dropping of the stepchild adoptions provisions as unacceptable, since the law currently does not protect the children of same-sex couples. The knock-on implications should the biological parent of such a child die or be incapacitated most typically include children being removed from their family home to be placed with their remaining biological parent or even being placed into care.

‘If government [coalition] agreement means giving up on the stepchild [adoptions], I am against it,’ said Roberto Speranzo, a leader of the PD’s leftist faction.

PD senators will make their decision tomorrow when the upper chamber meets again to resume its voting on the bill, after a week was granted to allow all parties to consider their positions and their options going forward.

Hundreds of thousands of people marched in January in support of the reforms, although Catholic bishops have criticised the bill. In an unexpected turn, Pope Francis has refused to publicly endorse the stance of his bishops, meaning the Vatican has yet to make its official stance on the subject known.

When asked about his reluctance to involve himself in the debate on the bill, Pope Francis said, ‘The pope does not meddle with Italian politics. Because the pope belongs to everybody, he cannot enter the concrete, domestic politics of a country. This is not the pope’s role.’