(ANSA) - BELGRADE, JUN 6 - All trams, buses, and metros in Budapest have been stopped since midday at the request of Green mayor Gergely Karacsony, as a protest and warning against the capital's impending bankruptcy. The Orban government has long attempted to financially suffocate the city, which is led by the democratic opposition and serves as a stronghold against government authoritarian rule. The most recent proposal is an extraordinary tax known as the solidarity contribution, which would provide aid from the richest municipalities to the poorest. Under this title, the treasury collected 89 billion (225 million euros) from Budapest, leaving a 57 billion (140 million euro) hole in the capital's budget. (ANSA).