The family of a jailed British-Egyptian activist on Monday held a vigil outside the foreign ministry in London to highlight a call by 100 British lawmakers for "fresh approaches" to secure his release.
The pro-democracy and rights campaigner Alaa Abdel Fattah is serving a five-year prison sentence for "spreading false news" by sharing a Facebook post about police brutality.
He was a key figure in the 2011 revolt that topped Egyptian autocrat Hosni Mubarak, and was given British citizenship in 2022 through his British-born mother.
The lawmakers voiced concern about the lack of progress despite Prime Minister Rishi Sunak raising the case directly with Egyptian President Abdel Fattah Al-Sisi during the COP27 climate summit in November last year.
"Private lobbying of the Egyptian government even at the highest levels is yet to deliver results. This calls for fresh approaches," the lawmakers from the lower and upper house of the UK parliament say in a letter to Foreign Secretary James Cleverly which was submitted on Monday.
French President Emmanuel Macron also took up the 41-year-old's case with Sisi and US President Joe Biden raised human rights issues.
Abdel Fattah's sister, Mona Seif, told AFP the family wanted to see the British government make his case a "top priority".
"We are asking them to shift gear. They have been using this approach of soft diplomacy and raising Alaa's case for over a year-and-a-half now and they haven't received anything in return," she said.
Rights groups say there are more than 60,000 "prisoners of conscience" who have been jailed in Egypt under the rule of President Al-Sisi.
Sisi deposed Islamist president Mohamed Morsi in 2013, before being elected the following year.
- Hunger strike -
At the time of the climate meet in the Egyptian Red Sea resort of Sharm el-Sheikh, Abdel Fattah had been on hunger strike for seven months.
On the day the conference opened he had begun refusing water too.
The British lawmakers want the UK to "take the lead on a joint statement on Egypt" at the UN Human Rights Council and to update the UK's travel advice to align it with the United States.
The US government warns that US citizenship does not provide protection from detention or arrest in Egypt and that those detained may be subject to "prolonged interrogations and extended detention".
Abdel Attah's sister Mona added that she believed a joint statement on Egypt at the UN Human Rights Council would almost certainly be "effective" in persuading the Egyptian government to move on the case.
"We know that a lot of countries would be willing to join in on a statement... but it needs to be led by the UK government because they have a higher stake, they have one of their citizens in arbitrary detention," she said.
The lawmakers' letter adds that the British embassy in Cairo has been prevented from visiting Abdel Fattah in jail for the past 18 months.
His mother Laila Soueif, a mathematician, said she could not understand why the UK government had been unable to secure this and described the situation as "unacceptable".