A political comedy of errors has hurt Prime Minister Silvio Berlusconi's coalition less than a month before key regional elections, in the latest headache for a man already weighed down by a string of scandals.

In a fiasco that Italian newspapers said left Berlusconi fuming at his aides, his People of Freedom (PDL) coalition missed the deadline for registering candidates in Rome province for key regional elections seen as a test of national strength.

Rome province, the largest in the Lazio region of which Rome is capital, has more than 2 million voters. Thirteen of Italy's 20 regions will vote on March 28-29.

While not the largest or richest region up for grabs, Lazio is perhaps the most symbolic as it is the seat of the national government.

Losing it would be a major embarrassment for Berlusconi, who was shaken last month by a high-profile corruption scandal concerning the head of the civil protection agency, a close aide. Berlusconi also faces two trials, for tax fraud and for bribery. He denies all wrongdoing.

Lazio had been considered an easy win for Berlusconi's center-right coalition because the region's ex-governor, Piero Marazzo, a leftist, resigned after a sex and drugs scandal. But the weekend's events have destroyed that certainty.

In more trouble for the ruling coalition, a Milan court rejected the candidate list for regional elections in the northern Lombardy region presented by outgoing center-right governor Roberto Formigoni because of invalid signatures.

An appeal against that decision was expected on Tuesday.

Coalition in a mess

"The image that emerges from this is that of a coalition in a mess," Massimo Franco, commentator for the leading Corriere della Sera, wrote on Monday.

An opinion poll published last month showed Berlusconi's approval rating slipping to 46 percent after remaining at or above 50 percent for long periods. The new developments were certainly not good news coming four weeks before the elections.

Berlusconi's coalition said the deadline was missed because its representative was distracted outside the electoral office on Saturday by an argument with a member of another party.

But media reports and irate center-right bloggers spoke of bungling and incompetence in the party, which commentators said could only hurt Berlusconi's image.

The representative not only arrived at the last minute but did not have all the proper documents with him. Some reports said the deadline was missed because of internal bickering about names of candidates for regional councillors.

The bloggers warned that the fiasco could mean disaster for the party in Lazio, where Berlusconi's candidate for governor, right-wing trade unionist Renata Polverini, is running against the popular former European Union commissioner Emma Bonio.

Franco said there was a "poisonous atmosphere" between candidates who belong to Berlusconi's faction and those, including Polverini, allied with Gianfranco Fini, speaker of the lower house of parliament.

Fini, who headed the conservative National Alliance party before it merged with Berlusconi's PDL, is considered the leading candidate to eventually succeed Berlusconi as leader of the center right and a future prime minister.

The PDL's first appeal against the ruling on the missed deadline was rejected by a court on Sunday. It has filed another appeal to another court and if it fails there could take the appeal to two higher tribunals.