ROME (Reuters) - Italian Prime Minister Matteo Renzi got a political boost on Friday when eight members of a centrist party defected to join his ruling Democratic Party (PD), strengthening Renzi's fragile majority in the upper house Senate.
The defectors, including Education Minister Stefania Giannini, abandoned the Civic Choice movement which has steadily lost support since it was set up in 2013 by former Prime Minister Mario Monti.
Civic Choice was already part of the ruling coalition but joining the PD makes their support for the government even more solid. It also underlines the PD's shift to the right under Renzi, which has angered many of the party's old guard.
Five of the defectors are senators, bolstering Renzi's position in the upper house where he has had to rely on the support of the center-right opposition to try to push through a reform of the electoral law.
The others are two lower house deputies and Deputy Industry Minister Carlo Calenda, who is not a member of parliament.
In the most recent Senate vote on the electoral law 27 of the 107 PD senators refused to back Renzi.
Switching political sides is common among Italian lawmakers. The latest defections were as usual accompanied by accusations of careerism and treachery from the opposition, which were shrugged off by the PD.
"Welcome home to the five Civic Choice senators, the PD is the natural home for all reformists," said PD senator and close Renzi ally Andrea Marcucci.
There is wide speculation that the ranks of the ruling majority could soon be further strengthened by defections from the center-right, which is in growing disarray.
Around 10 senators from the center-right GAL party, whose stronghold is in the south of Italy, are considering switching to the center-left, one of the senators told daily Corriere della Sera on Friday.
(reporting by Roberto Landucci, writing by Gavin Jones)