Kolkata: Former Lok Sabha Speaker Somnath Chatterjee passed away at a private hospital on Monday morning following multiple organ failure. He was 89 years old.

Chatterjee passed away at around 8:15 am after his condition deteriorated following Sunday's "mild heart attack", said a hospital official from Belle Vue Clinic hospital where the former CPI(M) leader was undergoing treatment.

He was suffering from a kidney-related ailment and was admitted to the hospital in a critical condition on Tuesday last. He was in the ICCU and had been put on ventilator. Last month, the former speaker had suffered a haemorrhagic stroke.

A 10-time Lok Sabha MP, Chatterjee was a central committee member of the CPI(M), which he had joined in 1968. He was the Speaker of the Lok Sabha from 2004 to 2009.

The veteran leader was, however, expelled from the CPI(M) in 2008 for refusing to resign as the Speaker after his party withdrew support to the UPA-I government.​

CPI (M) leader Sujan Chakraborty said, “It’s a big setback for us. Today, we lost Somnath da around 8.15 am at a private hospital in Kolkata.”

Leaders from across the political spectrum mourned his death.

Prime Minister Narendra Modi condoled Chatterjee's demise and described him as a "strong voice for the well-being of the poor and vulnerable."

"Former MP and Speaker Shri Somnath Chatterjee was a stalwart of Indian politics. He made our Parliamentary democracy richer and was a strong voice for the well-being of the poor and vulnerable. Anguished by his demise. My thoughts are with his family and supporters," PM Modi tweeted.

Former MP and Speaker Shri Somnath Chatterjee was a stalwart of Indian politics. He made our Parliamentary democracy richer and was a strong voice for the well-being of the poor and vulnerable. Anguished by his demise. My thoughts are with his family and supporters. — Narendra Modi (@narendramodi) 13 August 2018

Congress Chief Rahul Gandhi also expressed his condolences. He tweeted: "I mourn the passing away of Shri Somnath Chatterjee, 10 term MP and former Speaker of the Lok Sabha. He was an institution. Greatly respected and admired by all parliamentarians, across party lines. My condolences to his family at this time of grief. #SomnathChatterjee"

I mourn the passing away of Shri Somnath Chatterjee, 10 term MP and former Speaker of the Lok Sabha. He was an institution. Greatly respected and admired by all parliamentarians, across party lines. My condolences to his family at this time of grief. #SomnathChatterjee — Rahul Gandhi (@RahulGandhi) August 13, 2018

Delhi Chief Minister Arvind Kejriwal, in a tweet said Chatterjee was "..greatly respected and admired by all parliamentarians, across party lines".

Extremely sad news about Somnath Chatterjee ji. One of the greatest parliamentarians of contemporary times he will always be missed by this country. He will be remembered among the greatest Lok Sabha Speakers India ever had. https://t.co/dpnsE9ME1a — Arvind Kejriwal (@ArvindKejriwal) August 13, 2018

Former Jammu and Kashmir CM and National Conference Chief Omar Abdullah also paid his tribute. "Rest in peace now Somnath da. It was an honour to have known you & to have learnt from you. The Lok Sabha was much the poorer by your absence in recent years. India has lost a parliamentary giant today," he said in a tweet.

Rest in peace now Somnath da. It was an honour to have known you & to have learnt from you. The Lok Sabha was much the poorer by your absence in recent years. India has lost a parliamentary giant today. #SomnathChatterjee — Omar Abdullah (@OmarAbdullah) 13 August 2018

Former Finance Minister P Chidambaram, in a tweet, expressed his deep sorrow over the passing away of Chatterjee.

"Saddened to learn of the passing away of former Speaker Somnath Chatterjee ji. Throughout his life he was a democrat, a liberal and a champion of enlarging the constituency for social democracy," he said.