The era of One-Party Dominance of the Congress Party was effectively broken in 1967. This was the year when Congress began losing its absolute dominance in many state elections and faced increasing competition from regional parties. The 1967 elections saw Congress's reduced majority and the rise of opposition parties in several states, signaling the beginning of a multi-party political system in India.
This shift was a significant turning point in Indian politics, where regional parties began to challenge the Congress party's hold on power.