By Girish Gupta
CARACAS (Reuters) - Two Venezuelan opposition politicians on partial hunger-strike in jail are losing weight, but maintaining their demands including the release of fellow imprisoned anti-government activists, their supporters said on Wednesday.
Leopoldo Lopez, 44, and Daniel Ceballos, 31, were imprisoned during months of anti-government unrest last year.
President Nicolas Maduro calls them criminals who want to unseat him, while their supporters abroad and in Venezuela view them as symbolic political prisoners.
A former Caracas district mayor, Lopez has for 10 days ingested only water and a nutrient serum, his family said.
"He's thin," his mother Antonieta Mendoza said in an interview. "He has lost six kilos (13.2 pounds) but I'm impressed by his strength and clarity of thought."
Ceballos, formerly the mayor of the western city of San Cristobal, stopped eating properly 12 days ago and appears to be in a worse physical condition, his supporters said.
He and Lopez were both held at the Ramo Verde military prison until Ceballos was transferred to a civilian jail at the weekend in the central state of Guarico after beginning a similar partial hunger strike.
The United Nations has expressed concern for Ceballos' health and in October Zeid Ra'ad Al-Hussein, the U.N. High Commissioner for Human Rights, called for Lopez's release.
Maduro says the jailed pair are responsible for more than 40 deaths resulting from last year's unrest and that he has no plans to order their release.
As well as the release of activists, the pair are demanding that electoral authorities fix a date for upcoming parliamentary elections to be held by the end of the year.
Split between radicals like Lopez and more pragmatic leaders, Venezuela's opposition Democratic Unity coalition has been lukewarm in its response to calls for protest.
However, coalition head Jesus Torrealba stood by Lopez's wife and mother at a press conference on Wednesday.
Rallies on Saturday, called for by Lopez in a video from jail, attracted thousands of opposition supporters.
"Once more, we have demonstrated that our fight is peaceful, not violent," said Lilian Tintori, Lopez's wife.
(Additional reporting by Tom Miles in Geneva; Editing by Brian Ellsworth.)