Constitutional practicability of referendum on EU Constitution

Yes. Binding referendum requires implementation by constitutional amendment. Consultative referendum expressly provided.

Approval of transfer of sovereignty with effect of constitutional amendment

Majority of votes from parliament, §§ 93, 94, 95 ConstFinland.

Approval of transfer of sovereignty with effect of constitutional amendment

Majority of 2/3 of votes from parliament, § 94 II ConstFinland. Limit for transferance is an endangerment of the fundamental democratical rights of the constitution, § 94 III ConstFinland.

Approval of constitutional amendment

Majority of 2/3 of votes from parliament after proposed constitutional amendment was approved by majority of votes from parliament and its new-election. Only if parliament declares with a majority of 5/6 of the votes a constitutional amendment as urgent it can be realised circumventing with majority of 2/3 of the votes, § 73 ConstFinland.

Other constitutional regulations about Referendums

Consultative referendum can be called, § 53 ConstFinland.