* Conte lacks solid majority in upper house Senate
* Efforts to lure centrist senators have had little success
* Key vote on justice system due this week
* Newspapers report Conte plans to resign, govt source denies it
By Giuseppe Fonte and Crispian Balmer
ROME, Jan 25 (Reuters) - Italian Prime Minister Giuseppe Conte looked for a solution on Monday to a political crisis that has enveloped his government, leaving him without a reliable majority in the upper house Senate.
Several Italian newspapers reported that Conte was set to hand in his resignation to the head of state this week and then try to put together a new, broader coalition, drawing up a policy pact for the remaining two years of the legislature.
However, a senior government source denied that this was Conte's plan. He did not immediately signal what the alternative strategy might be.
The government was thrown into turmoil earlier this month when a junior partner, the Italia Viva party headed by former premier Matteo Renzi, pulled out of the cabinet in a row over its handling of the coronavirus crisis and economic recession.
Although Conte survived a subsequent a confidence vote in parliament last week, he failed to secure an absolute majority in the Senate, meaning he will struggle to enact any policy agenda unless he can draw on new support.
The first major test will come this week, when the upper house votes on an annual report on the justice system. Such a motion is a formality for any stable coalition, but a number of centrist politicians who saved Conte last week have said they will not back him over this particular issue.
Defeat in the Senate would effectively kill off the government.
Resigning ahead of time would give Conte more time to try to stitch together a new administration.
Corriere della Sera newspaper said the prime minister wanted to get Renzi back on board and was looking to create a "government of national salvation", that would also have the backing of some moderate centre-right politicians.
If he fails to broaden his coalition, he would be forced to step aside, leaving the path for someone else to try to forge a new government, almost certainly built around the main parties currently in power -- the 5-Star Movement and Democratic Party(PD).
Ever since his partial victory in the Senate last week, Conte has appealed to centrist and unaligned Senate lawmakers to join government ranks, but few have responded so far.
Looking to put pressure on waverers, the main ruling parties have said snap elections, two years ahead of schedule, will be the only way out of the political impasse unless a solution is rapidly found.
A recent reform cut by one-third the number of parliamentary seats up for grabs at the next national ballot, meaning that many of the current lawmakers are unlikely to win re-election, whatever the result.
This means that there will be no rush in parliament for a vote, putting pressure on party leaders to find a compromise. (Editing by Gavin Jones)