The exclusion of Stefano Fassina leaves four candidates in the race for Rome's mayor.

The Lazio regional administrative tribunal (TAR) has upheld the exclusion of Stefano Fassina, Rome mayoral candidate for the small left-wing party Sinistra Italiana (SI), from June local elections on grounds of irregularities in the presentation of the supporting electoral lists.

Specifically, the court confirmed the decision of the local electoral commission to reject the lists on the basis of missing dates and the use of outdated forms in some cases.

Fassina, a former deputy economy minister and harsh critic of prime minister Matteo Renzi, has said he will appeal against the ruling to the Council of State, Italy’s highest administrative court.

Should his exclusion be confirmed, his votes will likely boost the chances of Movimento Cinque Stelle candidate Virginia Raggi, the current frontrunner in a race triggered by the resignation of Ignazio Marino of the Partito Democratico (PD) ostensibly over an expenses scandal last year.

The other main candidates are Roberto Giachetti of the PD, Alfio Marchini, a former independent candidate now backed by Silvio Berlusconi’s Forza Italia and junior government partner Nuovo Centro Destra, and Giorgia Meloni of the right-wing Fratelli d’Italia.

Fassina formed SI last November after breaking ranks with the PD in opposition to its reform agenda and refused to take part in centre-left primaries in March.

For more details of the candidates see related article.