(ANSA-AFP) - BUDAPEST, 12 APR - Hungarians began voting on Sunday in closely watched crunch parliamentary elections that could end nationalist Prime Minister Viktor Orban's 16-year stint in power as a self-described "thorn" in the EU's side. Polling booths opened at 6:00 am local time (0400 GMT), according to AFP journalists. They will close at 7:00 pm. Opinion polls suggest that the party of pro-European conservative Peter Magyar -- who has promised a "system change" -- is running well ahead of that of Orban. (ANSA-AFP).