International pressure mounted Tuesday for the immediate release of Egyptian activist Alaa Abdel Fattah, whose family fears for his life after he escalated his hunger strike by refusing water too as COP27 opened.

After a seven-month period during which he consumed only "100 calories a day," the 40-year-old British-Egyptian stopped drinking water on Sunday as world leaders gathered for the opening of the global climate summit in Egypt.

On Tuesday, a day after British Prime Minister Rishi Sunak and French President Emmanuel Macron met with Egypt's President Abdel Fattah Al-Sisi, UN rights chief Volker Turk, German Chancellor Olaf Scholz, and Sunak demanded the activist's release.

Abdel Fattah, currently serving a five-year sentence for "spreading false news" for reposting a Facebook post about police brutality, has been leading headlines during the UN summit, intensifying international attention on Egypt's rights record.

A key figure of the 2011 uprising that toppled Hosni Mubarak, Abdel Fattah gained the British citizenship this year through his UK-born mother, Laila Soueif.

"A day or two or three at most"

Soueif -- who has been camped out in front of the prison for two days in the hope of receiving a letter as proof of life, according to daughter Mona Seif -- warns her son may only have "a day or two or three at most."

Activists at COP27 have posted prolifically on Twitter under the hashtag #FreeAlaa and several speakers have ended their speeches with the words "you have not yet been defeated" -- the title of his book.

Macron claimed that he had received an assurance that Al-Sisi is "committed to ensuring that (the) health of Alaa Abdel Fattah is preserved" and that the situation will be resolved "in the coming weeks and months."

Cairo has faced intensifying criticism of its long deplored human rights record since it was announced as the host of the COP27 climate summit last year, a move rights groups said "rewards the repressive rule" of Al-Sisi.

Rights groups say the number of prisoners is 60,000, a claim denied by Cairo.

Abdel Fattah's continued detention comes despite Egypt having granted presidential pardons to a total of 766 political prisoners since the reactivation of a pardon policy in April this year, according to data compiled by Amnesty. 

But over the same period, close to double that number have been jailed for their activism, Amnesty added.