"The Prime Minister should tread cautiously. Just because NRIs have loads of money doesn't justify their getting voting rights," Thackeray said in an editorial in Sena mouthpiece 'Saamna'.
"India does not expect money from its sons who have settled abroad. It expects that they come and stay here for a while and guide locals and contribute to development by sparing their knowledge, time and experience. This is more important than voting rights," the Sena chief said.
"You (NRIs) should consider the country where you are based, as your motherland. Don't step on two stones, else you will be accused of dual loyalty," he said.
"A large number of Muslims in India are loyal to Pakistan and India has to bear consequences," he added.
The Prime Minister had recently indicated that Indian passport holders living abroad could get voting rights by the time of next Lok Sabha elections in 2014.