Days after calling upon the Congress to replace chief Sonia Gandhi over her foreign origin, NCP general secretary P.A. Sangma threw another stone into the troubled waters saying that Uttaranchal CM and veteran Congress leader N.D. Tiwari should be the Congress prime ministerial candidate.Sangma, who was here to participate in the first convention of NCP workers in Uttaranchal, compared Tiwari with famous footballer Ronaldo. ‘‘The world famous Brazilian soccer star Ronaldo can play well with international teams but how he can play with a village level team,’’ Sangma said.He said that it was a pity that such an experienced person like Tiwari, who had been four times UP Chief Minister and several times union minister, had been sidelined to head a small state like Uttaranchal. ‘‘Tiwari is the most experienced Congress leader to be their candidate for Prime Minister followed by Manmohan Singh and A.K. Antony,’’ he said.Asked whether he opposed dynastic rule when Rajiv Gandhi took over, Sangma said that he had advised Rajiv not to straightway become the Prime Minister. ‘‘I advised him to be a Union minister for at least five years,’’ he said.