In a stinging attack on the Left and BJP, Indian Congress President Sonia Gandhi on Wednesday said it was a "shame" that the two parties had joined hands in attacking Prime Minister Manmohan Singh using "bad and negative language". "It is a shame on the part of the BJP and the CPI(M) to attack Dr Manmohan Singh. When a person becomes a PM, whether he belongs to Congress or other party, he becomes the Prime Minister of the country," Ms. Gandhi said, addressing an election rally in Vatakara in north Kerala as part of her day-long whirlwind tour of the state. "I am shocked that senior leaders of the BJP and the Left are using negative language against our Prime Minister," she said as she fended off the attack by the saffron party, whose Prime Ministerial candidate L K Advani has repeatedly called Mr. Singh a "weak Prime Minister". "It was shameful that the Left joined the BJP in attacking the Prime Minister ignoring the fact he is endowed with integrity. We are fortunate to have a Prime Minister like him," Gandhi said as she took on the Communists in their stronghold state. Questioning the Left's track record on secularism, she said they had joined with the BJP twice and it was only the Congress, which never compromised with the ideology of BJP.