The Christian People's Alliance has come out in support of demands for new presidential and parliamentary elections following the controversial re-election of President Alexander Lukashenko in December.
It condemned last week's decision by Belarus to put more than 30 political activists on trial, including four opposition candidates.
The crackdown follows protests by opponents of Lukashenko following his landslide election victory on December 19.
The EU and US responded yesterday by imposing sanctions against Lukashenko and other officials prohibiting them from entering either territories.
Anglican vicar and CPA National Executive member the Rev Robert Hampson said "firm measures" were needed to force Lukashenko to free the detainees, which he said included members of the Belarusian Christian Democrats (BCD).
More than 700 people were arrested after a demonstration against the election result. BCD leaders Vital Rymasheuski and Paval Seviarynets were among a group of around 30 of those arrested who were charged with organising "mass riots", a crime which carries a sentence of up to 15 years.
Rev Hampson expressed concern for the welfare of members of the BCD and called for new elections.
"Belarus is one of the last authoritarian regimes in Europe," he said.
"We stand alongside our brave political friends in the Belarusian Christian Democrats and share their demands for new, free and democratic presidential and parliamentary elections without the participation of Alexander Lukashenko.
"Such elections must be run by a fully independent commission and the country's monopolistic state electronic media must be stripped of their role."