Rome, April 19 - Florence Mayor Matteo Renzi of the centre-left Democratic Party (PD) saw his popularity rise still further on Friday with over twice the rating of party secretary and centre-left leader Pier Luigi Bersani, the SWG polling agency said. The 38-year-old local administrator was polling 61%, up 5 points over the previous week. This compared to the 29% registered by Bersani, who nonetheless also saw his popularity rise by 2%. The PD secretary was followed by Beppe Grillo, the firebrand leader of the anti-establishment 5-Star Movement (M5S), and ex-premier and leader of the centre-right People of Freedom (PdL) party Silvio Berlusconi, who were neck-and-neck at 28%. Outgoing technocrat Premier Mario Monti, leader of the small centrist and reformist platform Civic Choice, trailed at 23%. The latest figures came against a backdrop of ongoing political deadlock after inconclusive general elections at the end of February led to a hung parliament and disagreements over the election of Italy's next president. Renzi's standing has grown since he publicly urged the PD and PdL to strike a deal or go back to the polls, while Bersani has been hurt by a perceived insistence on wanting a precarious PD-led minority government amid rising tensions within his party. Many now see the Florence mayor as a possible answer to the impasse, possibly at the helm of a broad coalition government supported by left and right. Renzi has also been boosted by Bersani's perceived mishandling of the presidential vote, after he allowed Berlusconi to pick a candidate, ex-Senate Speaker Franco Marini, who exposed deep divisions in the PD. The party has now swung behind two-time premier Romano Prodi, a former European Commission chief, in the hope that the rifts can be papered over.