Constitutional practicability of referendum on EU Constitution

Yes. Binding and consultative referendum can be held.

Regulation about a special transfer of sovereignty

International treaties which effect matters of national defense must be confirmed by national law, Art. 40c II ConstHungary.

Approval of transfer of sovereignty without effect of constitutional amendment

Majority of votes from parliament by presence of at least 1/2 of its members, Art. 30a I lit. b, 24 I, II ConstHungary.

Approval of transfer of sovereignty with effect of constitutional amendment

Not expressly regulated, but constitutional amendment required.

Approval of constitutional amendment

Majority of 2/3 from members of parliament, Art. 24 III ConstHungary.

Other constitutional regulations about referendums

As well initiatives, referendums, binding and consultative, demanded by the president, government, 1/3 of the members of parliament or the people, as referendums on laws can be called, Art. 26 VI, 28b, 28c, 28d, 28e ConstHungary.