In 1989, Roșca became one of the founders of the Popular Front of Moldova (of which the PPCD is a successor). He was executive president of the organization from 1989 to 1994. Between 1990 and 2009, he was a deputy in the Parliament of the Republic of Moldova.
In 2005, his party voted for the re-election of the Communist president Vladimir Voronin,[3] and he became the Parliament's vice-president (a post he also held from 1998 to 2001).
In June 2009, he was sworn in as Deputy Prime Minister of the Moldovan Government[4] However, he only held that position until September of that year.
In summer 2024 Roșca was convicted of influence peddling over the construction of a building and sentenced to six years in prison.[5]