ROME (AFP) - Tens of thousands of opposition demonstrators on Saturday marched through the streets of Rome ahead of a confidence vote in parliament that could force Prime Minister Silvio Berlusconi out of office. The main opposition Democratic Party (PD) laid on 18 special trains, 1,500 coaches and two boats to ensure its supporters could take part in the protest. We are here to send out a message of confidence and of change in Italy, said Democratic Party (PD) secretary Pier Luigi Bersani, addressing the rally. We cannot continue like this, Berlusconi must go home, we have to go forward in a new direction, he added. Earlier Saturday, scandal-hit Berlusconi attacked what he called a campaign of lies and slander against him, and said he would survive Tuesdays vote of confidence in parliament. The knife-edge vote in both houses of parliament could trigger his downfall or see the resilient Italian leader bounce back once again. Backed by his allies, the anti-immigrant Northern League, he has enough support in the Senate but lacks votes in the lower house after its speaker, Gianfranco Fini, led a walkout of some 40 lawmakers from his party.