By Sachin Ravikumar

LONDON (Reuters) - The mother of jailed Egyptian-British dissident Alaa Abd el-Fattah was taken to hospital on Monday night as she neared the 150th day of a hunger strike in protest against her son's imprisonment in Egypt.

Laila Soueif, 68, who has lost nearly 30 kg (66 lb) in weight since starting her fast in September, was admitted to St. Thomas' hospital after her blood sugar dipped to worryingly low levels, her daughter said in a post on X.

Abd el-Fattah, a software developer and blogger who rose to prominence as an activist in the 2011 Arab Spring, was jailed for five years in Egypt over a social media post, a sentence that followed several previous spells in prison, including before and after the uprising.

Soueif, a mathematics professor, has been on hunger strike, consuming only herbal tea, black coffee and rehydration salts, ever since Egyptian authorities failed to free Abd el-Fattah on a scheduled release date of September 29.

British Prime Minister Keir Starmer and Foreign Secretary David Lammy have raised Abd el-Fattah's case with their Egyptian counterparts a number of times.

Starmer met Soueif this month, promising to do everything he could to secure Abd el Fattah's release.

"We all are hoping for Laila's health," UK junior foreign office minister Hamish Falconer, who met Soueif along with Starmer this month, told parliament on Tuesday when asked about the case.

"The prime minister has undertaken to take every effort that he can in order to try and ensure Alaa's release," he added.

A representative for the Egyptian embassy in London did not respond to a request for comment.

Speaking to the U.N.'s Human Rights Council on Monday, Egyptian foreign minister Badr Abdel Atty said Egypt was working on implementing the country’s human rights strategy, including via activating a national pardons committee, launching a national dialogue and passing a new criminal law.

Abd el Fattah's former prison mate, Australian journalist Peter Greste, joined Soueif in the hunger strike for three weeks last month.

Speaking to Reuters outside the hospital, Abd el-Fattah's sister Sanaa said she was frustrated at the British government but still hopeful Lammy and Starmer might be able to secure his release: "I hope they feel the urgency."

(Reporting by Sachin Ravikumar, additional reporting by Nafisa Eltahir in Cairo and Will Russell and Vitalii Yalahuzian in London; editing by Ed Osmond, William Maclean)