Jaitley has been put on extra-corporeal membrane oxygenation (ECMO), which is used for patients whose lungs and heart are incapable of operating on their own.
Several political leaders came to the All India Institute of Medical Sciences (AIIMS) to meet the senior Bharatiya Janata Party (BJP) leader.
Former Uttar Pradesh Chief Minister and Bahujan Samaj Party (BSP) President Mayawati visited the hospital to meet Jaitley who has been admitted since August 9.
"Today I went to AIIMS to see former Finance and Defence Minister Arun Jaitley to enquire about his health. There I met his family members and with them, I prayed to God for the speedy recovery of Jaitley ji," she tweeted.
Bihar Chief Minister Nitish Kumar flew to Delhi on Saturday and directly went to the hospital from the airport.
Among other leaders, Union Minister Piyush Goyal, Jammu and Kashmir Governor Satya Pal Malik, and Congress leaders Abhishek Singhvi and Jyotiraditya Scindia also visited the hospital to enquire about Jaitley's health.
On Friday night, Union Home Minister Amit Shah and Uttar Pradesh Chief Minister Yogi Adityanath visited AIIMS to meet the ailing leader.
President Ram Nath Kovind, Prime Minister Narendra Modi, Lok Sabha Speaker Om Birla and top BJP leaders have also visited the hospital.
Jaitley was admitted to AIIMS on August 9 after he complained of uneasiness and weakness. Owing to his health condition, Jaitley had opted out of contesting the elections this year as well as taking up a ministerial role.
( With inputs from IANS )