Political activists in Syria have urged the country's rulers to free political prisoners and move away from using force against its critics.
Syria has enforced a state of emergency for 42 years
Over 200 opposition figures and intellectuals signed a letter calling for a new impetus towards reform.
Among their demands were the release of several activists detained in 2001, and moves towards political openness.
The call came on the third day of the Baath party congress in Damascus, which is expected to approve limited reforms.
On Tuesday, Vice-President Abdul Halim Khaddam, described as a veteran hardliner and architect of Syria's influence over Lebanon, announced his resignation.
Correspondents say some see the move as a sign of serious political disagreements within the Syrian political class.
The letter specifically referred to a time known as the "Damascus Spring", a period of tentative moves towards reform shortly after President Bashar al-Assad came to power in 2000.
During the Damascus Spring a number of democratic discussion forums, or salons, emerged around Syria's capital.
But the period ended swiftly in 2001 with a wave of arrests of key figures.
"Spring comes this year as previous years, grim, after it had bloomed in the year 2001," the letter read.
"But the forces of oppression... cracked down on it and extinguished the spirit of life, light and freedom."
President Assad briefly flirted with reform, but then pulled away
The letter specifically called for the release of human rights activists Ali Abdullah and Mohammed Raadoun, as well as two opposition MPs and figures including lawyers and economists.
There were also demands for full disclosure about the fate of missing people within Syria, and calls for guarantees for the safe return of political exiles.
The Baath party congress, which ends of Thursday, is the first to be held since the death of Mr Assad's father, former President Hafez al-Assad.
It is reportedly considering amending or annulling Syria's 42-year-old emergency law, which activists say permits arbitrary arrests and trials.