Laila Soueif has been on a hunger strike for 100 days, aiming to press the UK government to liberate her son.
Her son, Alaa Abd El-Fattah, is a prominent activist imprisoned in Egypt since the 2011 uprising.
Soueif's protest commenced in September outside the British Foreign Affairs office due to the lack of progress.
She has been subsisting on black coffee, herbal tea, and rehydration salts.
The UK government has acknowledged efforts to secure Abd El-Fattah’s release, with Prime Minister Rishi Sunak discussing the case with Egyptian President Abdel Fattah al-Sisi.