"Ishrat Jahan joined the BJP at our Howrah office yesterday," BJP West Bengal General Secretary Sayantan Basu told PTI on Monday.
Jahan was inducted to the party and her decision was celebrate by the Howrah BJP on Sunday, PTI sources said.
According to Basu the BJP is planning to organise a state-level celebration for Jahan.
Jahan was one of five women to challenge the triple talaq before the Supreme Court. In 2014 her husband divorced her over the phone from Dubai.
On Aug 22, 2017 the Indian Supreme Court ruled that triple talaq was in violation of the fundamental right to equality in the constitution.
"It is clear that this form of talaq is manifestly arbitrary in the sense that the marital tie can be broken capriciously and whimsically by a Muslim man without any attempt at reconciliation so as to save it," the judgment said.
Jahan says she has been receiving threats since the decision.
On Dec 28, 2017 the Lok Sabha passed the Muslim Women (Protection of Rights on Marriage) Bill, 2017, which criminalises the practice.