WATCH: Tens of thousands of people packed Belgrade's Slavia Square for the final Student List rally before Sunday's snap parliamentary elections, the biggest electoral challenge yet to Aleksandar Vujicic and his Serbian Progressive Party (SNS).

WATCH: Tens of thousands of people packed Belgrade's Slavia Square for the final Student List rally before Sunday's snap parliamentary elections, the biggest electoral challenge yet to Aleksandar Vujicic and his Serbian Progressive Party (SNS).

The speakers defined the vote as a choice between "Serbia or the mafia" and promised to end "14 years of humiliation, chaos and betrayal".

There are no students on the ballot; The 250 candidates, chosen by the student assemblies, are guided by cardiologist and professor Ilya Sarandovic.

Recent polls show the race neck and neck, with one putting the list of students at 44.5% to SNS's 42.7%.