Freedom of movement is the most essential right enjoyed within the EU, according to a vast majority of Bulgarians, a survey finds.
The Eurobarometer poll shows some 87% of Bulgarians approve the policy.
Following are common security (72%) and migration (68%) policies.
Some 81% of all EU members' citizens, and at least two-thirds of the population of each member, share the same view.
In addition, nearly half (49%) of Bulgarians trust European institutions, while 34% are mistrustful and 17% cannot say.
This is the sixth-biggest figure of support for the EU after Lithuania (55%), Malta (52%), Romania (52%), Luxembourg (51%) and Finland (51%).
The adoption of the euro, however, leaves Bulgarians divided, with 38% accepting and 50% rejecting it. Overall, 58% of the EU's population backs the adoption of the euro across the bloc.
Most of those supportive of the euro spreading across the EU are Eurozone members, 70% of whose population backs the measure. In non-Eurozone countries, only 33% are of the same opinion.
Nearly half of Bulgarians (48%) back further EU enlargement, above the 39% average for the EU.