Pope Francis paid his respects to Napolitano on Sunday.
Italy's former president Giorgio Napolitano, who died on Friday evening aged 98, will receive a secular state funeral in the chamber of deputies in Rome on Tuesday morning.
French president Emmanuel Macron is to attend the ceremony to bid farewell to Napolitano, reports news agency ANSA, in what is the first time that a non-religious state funeral will be held inside Palazzo Montecitorio.
The ceremony at 11.30 will be broadcast live by state broadcaster RAI 1, as well as on large screens set up outside in Piazza del Parlamento, according to news agency Adnkronos.
Members of the public have been queuing up to pay their respects at Palazzo Madama, the seat of the Italian senate in Rome, where the former two-time president is lying in state until Monday evening.
The country's most senior political figures, including premier Giorgia Meloni and president Sergio Mattarella, were among the mourners who visited the senate building on Sunday.
Pope Francis also made a surprise visit to show his "personal affection" for the late president and his family, as well as honouring Napolitano's "outstanding service to Italy", according to a statement from the Holy See press office, reports Vatican News.
Napolitano, who served as head of state twice from 2006 until 2015, was the first former communist to rise to Italy's presidency.
Italian and European Union flags on public buildings will fly at half mast and Tuesday will be an official day of mourning in Italy.
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