COLOMBO (Reuters) - Sri Lanka's cash-strapped government will need at least $5 billion in the next six months to maintain basic standards of living, including some $3.3 billion for fuel imports, the country's prime minister told parliament on Tuesday.

       "Only establishing economic stability not enough, we have to restructure the entire economy," said Ranil Wickremesinghe, who is working to prepare an interim budget to balance Sri Lanka's battered public finances.

       The island nation of 22 million is suffering its worst economic crisis in seven decades, with a shortage of foreign exchange stalling essential imports.

       (Reporting by Uditha Jayasinghe; Writing by Devjyot Ghoshal; Editing by Tom Hogue)