Supporters staged a small rally outside London's Myanmar Embassy on Thursday for two Reuters journalists sentenced to seven years in jail after reporting on massacres in Rakhine state.
The rally was attended by former Al-Jazeera journalist Mohamed Fahmy, who was detained in Egypt in 2013 and convicted of fabricating "false" news in support of the Muslim Brotherhood.
There was an international campaign for the release of Fahmy and two colleagues and they were eventually pardoned two years later.
"I'm here because advocacy works," Fahmy told AFP.
"These two journalists are in prison right now, clinging on any hope. International pressure on fragile governments who do not respect human rights and press freedom is the way to get these guys out of prison," he said.
The protest was called by the International Observatory of Human Rights and free speech group English PEN, who delivered a letter to the embassy for Myanmar's de facto leader Aung San Suu Kyi calling for clemency for the two reporters.
"She's turning a silent ear and not standing up for journalists, not standing up for freedom of speech," Valerie Peay, director of IOHR, said at the protest.
Wa Lone, 32, and Kyaw Soe Oo, 28, were each imprisoned for seven years this month for breaching the country's hardline Official Secrets Act while reporting on atrocities committed during the military crackdown in Rakhine state.
Suu Kyi, once garlanded as a global rights champion, has come under intense pressure to use her moral authority inside Myanmar to defend the pair but she has defended the sentence by saying that the case upheld the rule of law.