Prime Minister of Italy, Romano Prodi, has resigned, after the Italian Senate rejected his plans to keep Italian troops in Afghanistan, and expand a U.S. military base in the north of the country.

Italy’s president, Giorgio Napolitano, has not responded to the resignation. He is believed to be considering a number of options, including asking Mr. Prodi to stay on. He is said to be exploring the various options open to him with various political leaders.

Prodi’s resignation was prompted by the decision of members of his own government to join with opposition members in opposing a move to continue funding the deployment of 1,900 Italian troops in Afghanistan, and another to expand a U.S. air base in Vicenza, a city in Italy’s north-east.

Following the vote many members began calling “Resign!, “Resign!” Protesters who gathered outside the Senate chamber also took up the chant.

BBC correspondent Jonny Dymond in Rome says it is not a foregone conclusion that the government will fall.

Mr Napolitano has several options, of which dissolving parliament and calling new elections is the most radical.

He could also ask Mr Prodi to test his support with a confidence vote, ask him to form a new government, choose a different prime minister from the ruling coalition or appoint a government of technocrats.

A statement from the president’s office said he “reserves his decision” on Mr Prodi’s move.

The government hinted it may resign if the vote was lost which made it difficult for Prodi to continue in office, without at least offering his resignationn.

Ironically the vote on the moves was successful but fell short of the majority needed. 158 senators voted in favour, but that was two votes short of the required 160. 136 senators voted against the motion, while 24 abstained.

The Prodi government came to office in mid-May last year, partly on its decision to pull Italy’s troops out of Iraq. The country lost 33 soldiers in the war-torn country, including nineteen who died in a suicide bombing in Nassiriya.

The country became enraged over its involvement in Iraq in March 2005. Italy was first hit by the news one of its journalists, 56-year old Giuliana Sgrena had been kidnapped. The country was gripped by the drama in the days that followed as Nicola Calipari, a former war hero turned intelligence officer, negotiated with Sgrena’s kidnappers for her release. This was eventually achieved. Italy was in a jubilant mood as a result and was preparing a home-coming and hero’s welcome for Sgrena and Calipari.

That jubilation turned to rage as news filtered through that U.S. troops had fired on the car transporting Sgrena and Calipari to the airport for their return home. Calipari was killed in the incident, while Sgrena was badly wounded. Another Italian agent was also wounded.

Italy’s Foreign Minister Gianfranco Fini told the Italian parliament the following day the car carrying Calipari and Sgrena was not speeding and U.S. troops did not order it to stop, contrary to what U.S. officials said at the time. He did however say it was an accident, and dismissed allegations by Sgrena that the shooting was an ambush.