Congress leader Sonia Gandhi on Wednesday said she will not contest the upcoming Lok Sabha election because of her age and health concerns.

"Due to health and increasing age, I will not contest the next Lok Sabha elections,” the 77-year-old said in a letter addressed to her constituents in Uttar Pradesh’s Rae Bareli, the Lok Sabha constituency that she has represented in the Lower House of Parliament since 2004. “After this decision, I will not get the opportunity to serve you directly, but, certainly, my heart and soul will always be with you.”

On Wednesday, the former Congress president filed her nomination for a Rajya Sabha seat from Rajasthan. This will be her first stint in the Upper House of Parliament. Gandhi is expected to secure the seat that will be vacated by former Prime Minister Manmohan Singh.

Three Rajya Sabha seats in Rajasthan will become vacant when the terms of Singh and Bharatiya Janata Party leader Bhupendra Yadav end on April 3. The third seat was vacated in December after the Bharatiya Janata Party’s Kirori Lal Meena resigned after his victory in the state Assembly election.

In her letter, Sonia Gandhi talked about her family’s “deep ties" with Rae Bareli, expressing gratitude to her constituents who have previously elected her father-in-law Feroze Gandhi and her mother-in-law Indira Gandhi to the Lok Sabha.

“From then till now, this series has continued with love and enthusiasm through the ups and downs and difficult paths of life, and our faith in it has become stronger,” Gandhi wrote. “In the last two elections, you stood by me like a rock even in difficult circumstances. I can never forget this.”

Gandhi entered active politics in 1998 when she became the Congress party’s president, winning the Lok Sabha seat from Amethi the following year. She subsequently became the leader of Opposition in the House. She was also the chairperson of the Congress-led United Progressive Alliance, a coalition government that was in power from 2004 to 2014.