Italy faced a government crisis on Thursday after Interior Minister Matteo Salvini of the right-wing League party called for a new election.
Mr Salvini, also Deputy Prime Minister, said his party's coalition with the populist 5-Star Movement had collapsed over policy differences.
Premier Giuseppe Conte said he would convene Parliament as requested by Mr Salvini to seek a confidence vote, but showed his anger over what he called a move to "abruptly interrupt the actions of the government".
He urged Mr Salvini to explain himself to voters.
The two governing parties have been at odds overmany policy issues but tension spiralled on Wednesday after the Senate rejected a move by 5-Star to kill a EU-funded high-speed rail link with neighbouring France.
The major infrastructure project, known in Italy as TAV, is backed by the League and seeks to improve rail links across several European nations.
As tones hardened, Mr Salvini met Mr Conte on Thursday and later issued a statement saying the TAV vote clearly showed that the ruling coalition had collapsed. He called for a quick election.
"Let's go immediately to the Parliament and verify that there is no longer a majority, as was evident in the vote on the TAV, and quickly return the word to voters," he said.
If the government should lose a confidence vote, that could set the stage for a new election.
Late on Thursday, Mr Conte chastised Mr Salvini for urging legislators to interrupt their holidays for a confidence vote.
"It is not for the interior minister to decide the timing of a political crisis in which other institutional actors are involved," the premier said.
Mr Conte said he would be in touch with the speakers of both houses to work out when to convene Parliament.
"I already clarified with Salvini during our meetings that this crisis that he triggered will be the most transparent crisis in the history of the republic," Mr Conte said.
If a vote of no-confidence is passed, it would be up to Italy's president to call an election if he found no way of salvaging the government.
The League and the 5-Star Movement have said they don't want to see a government of non-political technocrats.
The timing of any election is critical, as Italy must submit a budget in the autumn and needs a majority to work out terms.
The EU's third-largest economy barely dodged an EU budget disciplinary process over its rising debt levels this year.
The 5-Star leader, Luigi Di Maio, responded to Mr Salvini's statement by saying his populist party was ready to go to an election.
But while Mr Salvini wants an immediate vote, Mr Di Maio sought to postpone it until after Parliament gave its final approval to a reform reducing the number of members, a vote that had been scheduled for early September.
Earlier on Thursday, the League complained of deadlock with 5-Star on a variety of issues, saying "it is useless to go on".
The high-speed train vote laid bare the deep divisions in the Italy's 14-month-old government, with the 5-Stars opposing it as costly and unnecessary, and the League supporting it as necessary for the economy and its core base of northern entrepreneurs.
After the vote, Mr Salvini told supporters in the coastal town of Sabaudia that "something broke in the last months" in the governing coalition.
The League listed other areas of contention between the two parties, including fiscal policies, energy, justice reform, regional autonomy and relations with Europe.
Mr Salvini said 5-Star's pet electoral promise, basic income, which the government passed, was a handout that did not create jobs.
