PATNA: In a fresh embarrassment to JD(U), senior party leader Shivanand Tiwari on Friday lauded Narendra Modi saying the BJP prime ministerial candidate has emerged as a 'potent force' in national polity.

His remark came a month after he heaped praises on Modi at his party's conclave in Rajgir.

Tiwari said he would be frank in admitting that Modi had come a long way from where he had begun as a tea seller in Gujarat decades ago.

"Modi has potential. That's why he has reached this stage where he is a contender for the PM's post," he said maintaining his stand at the JD(U) conclave in Rajgir last month.

He, however, lashed out at Modi on other counts.

"A person who does not have the knowledge of history and that too of his own party is not fit enough to become the country's prime minister," he said referring to Modi mistaking freedom fighter Shyamji Krishna Verma with Jansangh founding leader Shyama Prasad Mookherjee during a speech recently.

Describing Modi as 'intellectually bankrupt' , Tiwari regretted that BJP has nominated a leader for the prime minister's post who does not understand history and geography of the country.

"A prime ministerial hopeful should not only be equipped with knowledge of the country's history and geography, but must also have a perspective on resolving serious economic and political issues, besides tackling terrorism, Maoist insurgency and border issues with Pakistan and China," the JD(U) leader said.

Modi, he said, has not spoken on issues like price rise and inflation , appreciating value of rupee and declining foreign investment during his speeches.

"Instead, he (Modi) conducts himself as a warrior and wants to address all problems with use of brute force ... Modi wants to use a bulldozer to find the solution to all vexed problems - be it our borders or economy ," Tiwari said.