Former Italian finance minister Roberto Gualtieri joins the race for Rome's top job.

The electoral campaign of Rome mayor Virginia Raggi, who is seeking a second term in office, has received a significant boost from Giuseppe Conte, the former Italian premier who recently took the helm of the populist Movimento 5 Stelle (M5S).

Writing in Italian newspaper La Stampa on 9 May, Conte backed the outgoing mayor, who has held her post since June 2016, assuring her of "convinced and solid support, at all levels" from her party.

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"The Movimento 5 Stelle has an excellent candidate in Rome: her name is Virginia Raggi," wrote Conte, underlining that after "an initial phase" when Raggi had to break with the city's "past management" systems, "for some time now we have begun to see the clear fruits of this intense work and the Romans are realising it more and more every day."

The ex-premier's ringing endorsement of Raggi, 42, coincided with the candidature of Roberto Gualtieri - who served as finance minister under Conte - for the centre-left Partito Democratico (PD).

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The long-expected announcement from 55-year-old Gualtieri, who says he will contest the primaries on 20 June, was welcomed immediately with a post by PD leader Enrico Letta.

Speaking to reporters on 10 May, the Lazio governor and senior PD figure Nicola Zingaretti - who had been rumoured to throw his hat in the ring - described Gualtieri, as a "strong and credible candidate."

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Speaking to Radio RaiUno this morning Letta acknowledged that Zingaretti "would have been an excellent candidate but he is doing something else and he is doing it very well," namely managing the Lazio region and steering it through the covid-19 crisis.

Alongside Raggi, Gualtieri joins another prominent figure in the race for mayor: Carlo Calenda, the 48-year-old leader of the liberal Azione party, who has been a mayoral candidate for the last seven months.

Calenda - a former minister of economic development who parted ways with the PD in 2019 after it entered into coalition with the M5S - was quick to voice his criticism of the PD's choice to pick Gualtieri over Zingaretti.

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"From a political point of view, yesterday was a victory for Raggi and the M5S but more than anything else it was a suicide by the PD," Calenda told Radio24.

The centre-right has yet to field a mayoral candidate for the Rome elections which are expected to be held in October. Photo La Repubblica.

Mi metto a disposizione di Roma, con umiltà e orgoglio. Partecipo alle primarie del 20 giugno. Costruiamo insieme il futuro della nostra città: io ci sono!#insiemeperRoma#primarie20giugno #iocisono pic.twitter.com/n1Dg2rT3s0— Roberto Gualtieri (@gualtierieurope) May 9, 2021