The mother of British journalist Kieron Bryan said she hopes "common sense, and a sense of fair play and justice" will prevail.
Speaking as at a silent protest outside the Russian Embassy in London, Ann Bryan said the country has made its point and said her son should be released.
"Punishment should fit the crime and for what happened that day I think they've more than served their punishment," she said.Adding: "I just hope that common sense, and a sense of fair play and justice, will come out of this."
More top news
Rain for the northwest, dry and cold elsewhere
Rejecting a showdown with Ed Miliband, David Cameron's terms sent to broadcasters reveal his deep dissatisfaction with the debate proposals.
The owners of what some people claim to be the 'Welsh Holy Grail' are offering a cash reward for the ancient artefact's safe return.