siena italy former italian prime minister silvio berlusconi order thursday stand trial accuse bribe witness 2013 under-aged prostitution case legal source say berlusconi leader center-right forza italia go italy party charge pay piano player wild bunga bunga party give false witness trial end eventually acquit new trial begin tuscan city siena february source say long national election must hold may late 81-year-old four-times prime minister deny wrongdoing case always maintain party plush residence near milan nothing elegant dinner party new case lead unwelcome publicity berlusconi may much impact prospect election already undergo numerous trials various charge range outcomes supporters either care little legal problems believe assertion victim politically motivate prosecutors forza italia lynchpin center-right alliance set win seat election accord opinion poll although suggest party coalition secure absolute majority lead hang parliament berlusconi accuse pay pianist danilo mariani lie 2013 trial accuse sex 17-year-old moroccan nightclub dancer karima el mahroug good know italy stage name ruby heartstealer mariani also send trial allege perjury one numerous people prosecutors believe berlusconi pay give false testimony trial allege payments various witness handle different court around country accord location bank receive money berlusconi originally find guilty pay sex minor sentence seven years jail verdict overturn 2014 appeal court rule proof know mahroug age berlusconi political career dog non-stop legal battle conviction tax fraud 2013 bar office month ask european court human right overturn ban italy 's berlusconi send trial accuse bribe witness source