Bhubaneswar, Aug 5 - Orissa Chief Minister Naveen Patnaik has urged Prime Minister Manmohan Singh to stop neighbouring state Andhra Pradesh from setting up the controversial Polavaram irrigation project, saying it would submerge many tribal villages in his state.

Patnaik, who met the prime minister in New Delhi Tuesday, also opposed the central government's move to accord 'national status' to the Indira Sagar Polavaram multipurpose irrigation project, being built on river Godavari at an investment of Rs.10,150 crore.

'The chief minister strongly objected to the declaration of the Polavaram project as a national project and requested him (the prime minister) to issue instructions to stop construction of the project as it will submerge large number of tribal villages in Orissa,' said a statement issued by the chief minister's office Wednesday.

According to state government officials, once the project is completed the back water of river Godavari will flow to its tributaries Saberi and Sileru in Orissa and Chhattisgarh and submerge dozens of bordering villages during floods.