The leader of Italy's anti-establishment Five Star Movement (M5S), Luigi Di Maio, said Tuesday that if his party can strike a coalition deal with the far-right League a "bomb" will hit a political system fearful of change.
The two parties have been locked in talks to reach a coalition government agreement and bring an end to two months of political deadlock following inconclusive elections.
However after negotiations had looked promising ahead of a deadline on Monday, they were extended when League leader Matteo Salvini laid down conditions on the "key issues" of immigration and policy regarding the European Union.
On Tuesday both men stressed that they had only been negotiating for six days, compared with the six months of torturous post-election bartering before a government could be formed in Germany.
In a Facebook video, Di Maio said that the establishment feared change but "the more they attack us the more I am motivated" to reach a deal.
"I see in a certain establishment such a fear of change," he said.
"If we get there it will be a bomb -- but a bomb in the positive sense. With courage we will succeed in returning citizens their rights and returning Italy to her rightful place on the European stage."
EU Commission vice-president Jyrki Katainen had warned on Tuesday against the formation of a government that might disregard the terms of the EU's stability and growth pact.
Di Maio shrugged off such warnings as the protests of "Eurocrats that nobody elected".
Salvini, saying he was "optimistic but realistic" about a deal, took rhetorical aim via social media at EU migration commissioner Dimitris Avramopoulos.
"That's enough! Yet more unacceptable interference from someone never elected. We have taken in and looked after too many (migrants). Now it's time for legality, security and expulsions," Salvini said.
Salvini said the League wanted "strong government and a tax and security revolution," but admitted it remained "far apart" from M5S on several issues.
He also said the only alternative to a deal was another election.
Di Maio said that any accord would be put to party supporters for online approval and full details would be available for their perusal by the weekend.
The two parties won more than 50 percent of the March vote between them as they look to lead the eurozone's third largest economy.
Anti-establishment Five Star Movement leader Luigi Di Maio says if his group can strike a deal to govern with the far-right League it will be a "bomb in the positive sense" detonating over Italy's political establishment
Leader of the far-right League Matteo Salvini admitted that his party and the M5S were still far apart on several issues, including migration and security