New Delhi, Apr 29 (IANS): Union Minister and Lok Janshakti Party (LJP) chief Ram Vilas Paswan on Monday hit out at the opposition parties for raising the issue of Prime Minister Narendra Modi's caste background and called them frustrated as they know they are "losing elections".

Addressing the media here, Paswan asked "what problem" Congress leader Priyanka Gandhi Vadra and Bahujan Samaj Party chief Mayawati have if Modi's caste is listed in "backward" category.

"What is hurting them? When Modiji had become Chief Minister of Gujarat, he was abused over his caste then. Now, they are raising it again. It is their frustration as they know they are losing the elections," he said.

On Sunday, Mayawati had claimed that Modi got his caste included among the Other Backward Class (OBC) communities for political gains. Vadra, however, denied that her party ever raised questions about Modi's caste.

Earlier, Modi had "requested" the opposition parties not to drag him into caste politics.

Paswan said the LJP-Bharatiya Janata Party-Janata Dal (United) alliance would win all 40 seats in Bihar.

"We expect the NDA (National Democratic Alliance) will win all 40 seats and we are cent per cent sure about 35 seats," he said.

Paswan also said Gandhi chose not to contest against Modi in Varanasi as she was "scared".

He claimed that the NDA will win Lok Sabha polls with majority and Modi will become Prime Minister again.