ROME (Reuters) - The leader of the anti-establishment 5-Star Movement, Luigi Di Maio, said on Monday that Italy should quit the euro zone unless it manages to change the bloc s rules on public finances. 5-Star, which leads in opinion polls ahead of an election expected in March, says if it wins power it will lobby Italy s EU partners to loosen the so-called Fiscal Compact which imposes steep budget cuts for high-debt countries like Italy. The maverick party threatens to hold a referendum on Italy s euro membership unless it is allowed to boost public investment and raise the budget deficit above the current limit of 3 percent of gross domestic product. Di Maio has recently softened the party s anti-euro rhetoric, saying 5-Star is  pro-Europe  and calling the euro referendum a  last resort  to be used only if Italy is unable to win any concessions.  If we should arrive at the referendum, which for me is a last resort because first I want to go to Europe and try to change a series of rules ... it s clear that I would vote to leave, because it would mean Europe hasn t listened to us on anything  he said in a television interview on Monday.  But today I see an opportunity for Europe (to reform) , he told the private station La7. Former Prime Minister Matteo Renzi, the leader of the ruling Democratic Party (PD), said in a tweet that  this time Di Maio has been clear... he would vote to leave the euro. I say it would be madness for the Italian economy.  The PD, which has split under Renzi s leadership, lags 5-Star by some 4 percentage points in most opinion polls, but no party or coalition is seen winning an outright majority at the election, which is expected to result in a hung parliament. 