Advocate Lily Thomas, the senior-most female lawyer in the Supreme Court, died on Tuesday at a hospital in New Delhi at the age of 91, Bar and Bench reported.

Thomas was known for several public interest litigations she filed in the Supreme Court. The most famous of these was her plea against allowing convicted lawmakers to continue as members of Parliament. The Supreme Court in 2013 struck down Section 8(4) of The Representation of the People Act, 1951, which protected sitting MPs and MLAs who were convicted of crimes from disqualification.

The former United Progressive Alliance government prepared an ordinance to retract the ruling. In response, Thomas filed a review petition in the Supreme Court. After prolonged backlash against the ordinance, the Congress-led government withdrew it.

Thomas had also filed a petition challenging Section 494 of the Indian Penal Code, which prescribes a jail term of up to seven years for those who marry again during the lifetime of their husbands or wives.

Advocate Sanjay Ghose offered his condolences on Twitter. “Nonagenarian Lily Thomas whose indefatigable zeal to fight for a better India saw the SC [Supreme Court] hand down landmark verdicts to clean up the polity, including disqualification of convicted netas, passed away in a India, sadly on a day when again defection & money power triumphed,” he tweeted.

“Boldness is the indispensable disposition and quality for women lawyers,” Supreme Court advocate Mrinal Kanwar tweeted, quoting Thomas. “Study of law is an extremely liberating and strengthening experience. It helps in personality development.”