VIENNA (Reuters) - Crimea's planned March 16 referendum on joining Russia is illegal in its current form and the OSCE will not send a mission to observe it, the Swiss head of Europe's security and democracy watchdog said on Monday.
Russia's RIA news agency said on Monday that Ukraine's Crimea region had invited the Organisation for Security and Cooperation in Europe (OSCE) to send a mission to observe Sunday's plebiscite. It said the invitation had been issued to the Vienna-based security and human rights organisation by the region's pro-Russian parliament.
"In its current form the referendum ... is in contradiction with the Ukrainian constitution and must be considered illegal," Swiss Foreign Minister Didier Burkhalter, whose country is the current chair of the Vienna-based OSCE, said in a statement.
"For any referendum regarding the degree of autonomy or sovereignty of the Crimea to be legitimate, it would need to be based on the Ukrainian constitution and would have to be in line with international law."
He also "ruled out the possibility of an OSCE observation of the planned referendum...as the basic criteria for a decision in a constitutional framework were not met," the statement added.
An OSCE spokeswoman said earlier that Crimea could not invite referendum observers as the region was not a full-fledged state and therefore not a member of the 57-member organisation.
For the past week, OSCE military observers have been unable to enter Crimea, which has come under control of Russian forces since the fall of pro-Russian Ukrainian President Viktor Yanukovich to months of popular unrest.
(Reporting by Fredrik Dahl; Editing by Mark Heinrich)