Koel Mallick joins the BJP and will file for the Rajya Sabha seat she left in July

Rukmini Mallick, the Bengali film actor known as Koel Mallick, joined the Bharatiya Janata Party on Monday at its state office in Salt Lake, Kolkata, and said she would file her nomination the same day for a Rajya Sabha seat. It is the seat she vacated in July, when she resigned from the Trinamool Congress after the party's defeat in the West Bengal assembly election.

Her Trinamool term in the upper house ran from 6 April to 16 July. That is 101 days. The BJP nominated her on Sunday. State general secretary Sashi Agnihotri, also spelled Shashi Agnihotri in some reports, handed her the party flag and said she would file on Monday. Anupam Ghosh, convener of the party's media department, and co-convener Chandrashekhar Basotia were at the office.

Mallick told the press conference it would be an honour to sit in the upper house and work for people's welfare. She said West Bengal had been on a path of development in recent months, that she wanted more of that work, and that she thanked Prime Minister Narendra Modi and Chief Minister Suvendu Adhikari for the nomination. Adhikari leads the first BJP government in the state. Her switch had been signalled weeks earlier by a meeting in New Delhi with Union minister Bhupender Yadav, after the resignation.

She is the daughter of Ranjit Mallick, one of the senior names in Bengali commercial cinema. Her own career has been in that industry. The political fact on Monday is narrower than the film biography. A former ruling-party MP is filing, under a new party, for the vacancy her resignation created, in a state the BJP now governs.

The election is on 16 October. It is one of 12 Rajya Sabha seats being filled that day across Uttar Pradesh, Uttarakhand and West Bengal. A Rajya Sabha by-election is decided by the state assembly, not by a public vote. With a BJP majority in Kolkata, a nominated candidate who files a valid paper is the likely winner. The interesting number is not the likely result. It is the gap between 16 July and 5 October: less than three months from resignation to a nomination by the party that beat her old party.

Trinamool has not, in the copy filed on Monday morning, said whether it will put up a candidate against her. A contest would force the assembly vote into the open. An uncontested filing would return her to the same seat with a different whip. Either way, the upper house loses a Trinamool vote from Bengal and, if she wins, gains a BJP vote, for the remainder of the term she originally held.

Mallick's line at Salt Lake was about development work under the new state government. She did not, in the statements carried by PTI, discuss the assembly result, the length of her first term, or the films. The desk record is the dates: MP from 6 April, resignation effective around 16 July, flag handed over on 5 October, poll on 16 October.