Mobilisation of voters, and the role of election monitors, played a big role in the opposition victory in both countries.

Last weekend, the DE civic action group in Hungary sent 70 election monitors to Serbia, to work with students' movement representatives, visiting polling stations in the northern Serbian province of Vojvodina.

During the summer, even before the election was called, they held workshops to share their experience and methods from the Hungarian election with the Serbian students.

A key technique was to identify "infected" polling districts in advance - places where the surprisingly high number of votes for the governing party at previous elections suggested that voter intimidation or "chain voting" techniques were used.

"From around 16:00 on election day, we noticed groups of masked hooligans - Vučiċ supporters - gathering near voting stations," Péter Klemm, a student activist from Subotica, told the BBC.…