India's independent Election Commission has declined to enter into a proposed tie-up with U.S.- based internet giant Google for voter facilitation services during the upcoming general elections over national security concerns, sources said Thursday. "The decision not to go into a tie-up with the global search engine came due to concerns over national security raised by all major political parties," the sources said. Google had recently submitted its proposal to the Election Commission for voter facilitation services in the polls slated for May this year, in which it also offered free online voter registration apart from making available vital details of voter electoral photo identity card numbers and polling station location. India's elections are the world's largest polling exercise in democracy, which take weeks to complete and involve hundreds of millions of voters. Over 700 million people are expected to vote in the upcoming polls to be held through electronic voting machines.