"Our opponent's communal agenda is a grave threat to our country's unity and integrity and Congress is the only party that can ensure that the country remains united," she told an election meeting.
Hitting out at the opposition for propagating "falsehood and charges of corruption", the UPA chairperson said "in every instance, we have taken corrective action. I want to challenge them here. I am challenging them to make such claim in states ruled by them."
"I want to ask them what kind of change are they talking about?. What kind of change are people of India thinking about? Do the people of India truly give up the values they cherish.. and trust those who have 'hitched their political careers on falsehoods and blatant lies"? she said.
A combative Sonia Gandhi said "can the people trust those who keep changing for personal and political gains? Can the people trust those who pretend to be moderate for narrow political gains? Let no one be under such an illusion.."
Attacking CPI-M led LDF in Kerala, she said Congress was fighting a different battle in the state against a 'rigid' ideology. "Our principal opposition are prisoners of an ideology that has no relevance in today's world," she said.
While Congress follows the principle of non-violence taught by the Father of the Nation, the Left Front rejects this principle, she said.
"What only matters to us is that we are all Indians. The different religions, castes, languages and colours of the skin do not matter," she said.
"We believe in an India that unites our people while the opposition seeks to divide. Our ideology binds our people together, their ideology separates one Indian from the other," she said.
"Congress-led UPA wants a united India where democratic institutions at all levels are strong. But the opposition is seeking to weaken institutions by 'one-man rule', Gandhi said referring to BJP's Prime Minsiterial candidate Narendra Modi.
"The choice before us is an India that belongs to all of us led by a government working for an India that belongs to all of us or an India that belongs to some of us and serves the interest of only a few," she said.
Gandhi, who arrived in Kochi this evening for addressing the election meeting at Thrissur, had to leave by road due to heavy rains.
The Congress president introduced the Congress candidates -- K P Dhanapalan (Thrissur), P C Chacko (Chalakudy) and Sheeba (Alathur).
Image: Congress President Sonia Gandhi
The many smiles of Rahul Gandhi: Vote for your favourite!
BJP doesn't respect you; see what they did to Advani: Rahul
Lok Sabha elections 2014: The battle begins on Monday
Rahul can't save his party, how will he save the nation: Modi
Left seeks EC's intervention for fair polls in Bengal