Italian Prime Minister Giuseppe Conte on Monday told Parliament a contested reform of the eurozone’s bailout fund was in Italy’s national interest – but that it should only be adopted as a package alongside other measures.

A reform of the European Stability Mechanism (ESM) is due to be approved by the bloc’s countries this month, but Italy‘s right-wing opposition is against it, and has accused Conte of “betrayal” by consenting to the changes without involving Parliament.

Any delay to its approval would be a new setback for the 19-country euro bloc, which has for years failed to complete key banking and financial reforms, leaving the euro currency exposed to new risks of survival in the event of a fresh major crisis.

“We can affirm that the negotiation conducted thus far has reached a balance in line with the national interest,” Conte told the Chamber of Deputies, listing numerous occasions when he said he had informed Parliament of progress in negotiations.

However, he said other measures, including a common bank deposit guarantee and a common unemployment insurance mechanism, need to be adopted along with the ESM changes, in addition to further progress on a eurozone budget.

Negotiations on these reforms are far less advanced, and it remains unclear whether Conte is threatening to veto the ESM reform until they are passed, or merely wants informal guarantees on them from Italy’s partners.

In an overture to Italy, which fears the overhaul may raise its debt servicing costs, a senior EU official in Brussels said a short delay of the ESM reform “by one or two months” could be acceptable – but would not be the best option. Italy’s debt is proportionally the highest in the eurozone after Greece.

The official acknowledged that could be seen as a setback for the eurozone, which was expected to finalise the agreement at a meeting of eurozone financial ministers on Wednesday and at a summit of leaders on December 13.

The ESM reform divides Italy’s ruling parties. The anti-establishment Five Star Movement is against signing off on it until plans for a wider European banking union become clearer, while the centre-left Democratic Party (PD) supports the plan.

Conte, a technocrat who is not from either party, is trying to broker a deal between them while fending off fierce attacks from Matteo Salvini’s right-wing League.

“On the government benches, there is someone who is lying,” Salvini told the Senate after Conte’s speech, referring to the premier. “The person putting at risk the savings of Italians is sitting there, he should be ashamed of himself.”

Debt concern

The proposed reform of the ESM would make it the backstop for the bloc’s fund for ailing banks, give the fund more powers to handle financial crises, broaden the eurozone’s monitoring powers over countries with economic imbalances and, if required, facilitate the restructuring of government debt.

Critics say the changes could make it more likely Italy will have to restructure, or even default on its debt, assertions that EU officials dismiss as unfounded and misleading.

After meeting coalition officials late on Sunday, Conte said the dispute would be settled by a vote in Parliament on December 11.

Government officials told Reuters that Rome’s main concern, on which it was ready to impose a veto, is to obtain a guarantee that sovereign bonds will not lose their status as risk-free assets under European banking union.

“In particular, what we don’t want is that public debts are risk-weighted according to the credit rating of the countries, which would be very damaging for us,” Maria Cecilia Guerra said on the margins of a conference in Milan.

This proposal was made last month by German Finance Minister Olaf Scholz in return for Germany potentially dropping its resistance to common deposit insurance.

In his speech in Parliament, Conte, often interrupted by opposition heckling, said Italy’s public debt was “fully sustainable” and there was “no reason on the horizon” why it should need to seek assistance from the ESM.

He also said Italy would seek changes to a technical aspect of the reform which would require countries to issue bonds with conditions attached, known as “single-limb Collective Action Clauses”, which would make debt restructuring easier.

These would prevent holdout investors from blocking a debt restructuring to get a better deal.

Italy will push to make these CACs more flexible to protect small investors, Conte said, introducing a further element hindering smooth approval of the reform by the eurozone.

In the event of losses from a debt restructuring, such as those suffered by Greek creditors in 2011, smaller investors could enjoy better terms with the reform, as the restructuring process would be faster, a second EU official said.