ROME (Reuters) - Italian Prime Minister Matteo Renzi's party has slipped in voters' estimation in recent weeks since a minister quit in connection with an influence-peddling probe, a poll indicated on Sunday.
Renzi's Democratic Party (PD) recorded its lowest rating since last summer in the Demos poll, published in La Repubblica newspaper, which indicated it would get 30.1 percent of the vote if an election were held now.
Federica Guidi resigned as industry minister last month after police released phone taps appearing to show her assuring her partner that the government would pass legislation that favored his energy business.
Guidi is not under investigation in the case, but Renzi appeared to acknowledge on Saturday that revelations trickling out in the press had caused him discomfort.
"It has been a difficult week," he told a meeting of young party members in Rome.
Renzi remains Italy's most popular political leader but his personal approval rating has dropped slightly since February and by almost half since summer 2014, shortly after his party won a resounding victory in European elections.
A separate survey in Corriere della Sera found 80 percent of people thought the probe was undermining the government's credibility to some extent, although a majority of those who followed it closely agreed with Renzi's statements about it.
The Demos poll had the anti-establishment 5-Star Movement snapping at the heels of the PD, which is still Italy's largest party, closing the gap to less than three points.
Just before Guidi resigned, another scandal had been prompted by a minister's family connections to a failed bank. Forty-five percent of people surveyed said the government had too many conflicts of interest and should step down.
The survey also found that, in the second round of voting that could be triggered by electoral reforms passed last year, the PD would have a very slim lead over the fractured center-right, but be defeated by the 5-Star Movement.
The next parliamentary election is not due until 2018, although instability within the ruling coalition often prompts speculation it could come earlier.
(Reporting by Isla Binnie; Editing by Kevin Liffey)