Sukhendu Sekhar Roy, Sushmita Dev and Prakash Chik Baraik resigned from the Rajya Sabha in June after questioning the Trinamool Congress (TMC) leadership following the party’s defeat in the 2026 West Bengal Assembly elections, which ended Mamata Banerjee’s 15‑year rule (corroborated across multiple outlets).

Sushmita Dev’s resignation was accepted with effect from June 10, 2026, and Prakash Chik Baraik resigned on June 11, becoming the third TMC Rajya Sabha MP to quit within a week (TheStatesman.com). Earlier reports indicated that two TMC Rajya Sabha MPs were likely to resign (Bluesky). The resignations also included Sukhendu Sekhar Roy, as confirmed by multiple sources.

After leaving the TMC, all three former MPs formally joined the Bharatiya Janata Party in Kolkata (Times of India). Sushmita Dev said her departure from the TMC was driven by political and personal reasons (Times of India). Prakash Chik Baraik had entered the Rajya Sabha from West Bengal in August 2023 (TheStatesman.com). Sushmita Dev had joined the TMC in 2021 after leaving the Congress and is the daughter of Assam Congress veteran Santosh Mohan Dev (TheStatesman.com).

The Election Commission of India has scheduled by‑elections for three Rajya Sabha seats from West Bengal on July 24 (The Hindu).