Italy's President Sergio Mattarella was set to dissolve parliament on Thursday ahead of an election widely expected to be held on March 4.
Following are the main parties and leaders, some of their key policies, and how they stand in opinion polls:
Ruling Democratic Party, leader Matteo Renzi (42)
Policies: negotiate with Italy's partners to abolish the EU's Fiscal Compact which imposes steep budget cuts on high-debt countries such as Italy. Raise the budget deficit to 3 percent of gross domestic product for five years in order to cut taxes and increase investment. Continuity in social and foreign policy, with Italy maintaining its traditional pro-NATO stance.
Support sliding in opinion polls, now at around 23 percent.
5-Star Movement, leader Luigi Di Maio (31)
Policies: universal income support to ensure monthly income of at least 780 euros ($925); renegotiate the Fiscal Compact; raise the budget deficit above 3 percent of GDP to cut taxes and increase investments; hold a referendum on euro membership if partners refuse any concessions on the Fiscal Compact; cut privileges of politicians, trade unions and well-off pensioners; repeal 2011 pension reform to allow earlier retirement; repeal 2014 labour reform to make firing harder; raise taxes on banks and oil and gas companies; toughen conflict of interest rules; cut red tape, abolishing 400 laws; scrap public financing of newspapers; separate banks' retail and investment arms; improve relations with Russia.
Italy's most popular party, according to polls. Support stable at around 28 percent.
Forza Italia, leader Silvio Berlusconi (81).
Policies: Introduce parallel currency for domestic use to boost the economy while keeping the euro for international trade and use by tourists; replace current staggered income tax rates with a single rate "flat tax" of around 23 percent for both individuals and companies; double monthly minimum pensions to 1,000 euros; abolish housing tax, inheritance tax and road tax on most cars; tax breaks for pet owners; guarantee minimum income of 1,000 euros per month for everyone; block the arrival of immigrants through accords with North African countries. Berlusconi is pro-NATO but boasts of his friendship with Russia's Vladimir Putin. Berlusconi cannot run at the election due to a tax fraud conviction. He has not yet said who Forza Italia's candidate for prime minister will be.
Support rising, around 16 percent, making it the most popular party in a centre-right coalition expected to win most seats at the election.
Northern League, leader Matteo Salvini (44).
Policies: Parallel currency for domestic use; push for abolition of the Fiscal Compact and Stability Pact; leave the euro as soon as it is politically feasible; "flat tax" for individuals and companies at 15 percent; repeal 2011 pension reform to allow earlier retirement; immigration crackdown by intercepting and sending back migrant boats and repatriating up to 100,000 illegal immigrants per year; toughen penalties for violent crime; improve relations with Russia.
Support slipping, around 13 percent.
Brothers of Italy, leader Giorgia Meloni (40).
Policies: Immigration crackdown by intercepting and sending back migrant boats and repatriating illegal immigrants; toughen penalties for violent crime; improve relations with Russia. Policies generally close to the Northern League's but unlike the League, its support is based in central and southern Italy.
Support stable at around 5 percent.
Free and Equal, leader Piero Grasso (72)
Left-wing party formed this month to unite small movements which had left the PD in dissent with Renzi, who they said had moved it too far to the right.
Policies: Repeal 2014 labour reform to make firing harder; soften 2011 pension reform to end automatic increases in the retirement age on the basis of rising life expectancy, increase spending on education, health and public works; improve relations with Russia and fully recognise state of Palestine.
Support rising gradually, around 7 percent.