Britain and canada have imposed sanctions against alexander lukashenko, the belarus president, and other high-profile regime figures.
The sanctions are due to come into force from tuesday and include a travel ban and asset freeze. it is the first time the uk has targeted a national leader with its own sanctions.
Belarus has been besieged with mass protests since august following the contentious sixth election win of mr lukashenko, who claimed to have won 80 per cent of the vote in an election widely decried as rigged.
The uk move comes as an eu effort to impose its own belarus countermeasures is held up by cypruss lone refusal to give the go-ahead, unless the bloc also imposes sanctions on turkey.
In a statement on tuesday, british foreign minister dominic raab said: today the uk and canada have sent a clear message by imposing sanctions against alexander lukashenko's violent and fraudulent regime. we dont accept the results of this rigged election.
We will hold those responsible for the thuggery deployed against the belarusian people to account and we will stand up for our values of democracy and human rights.
Mr lukashenko, who has been in power for 26 years, has come under fierce international criticism for his handling of the election and the violent treatment of the protesters, many of whom have been attacked with water cannon and arrested by riot police.
Britains foreign office said the sanctions formed part of a co-ordinated response with canada and had been issued in a direct response to the alleged torture and mistreatment of the protesters.
Speaking in the house of commons last week, mr raab argued the uk needed to advocate for democracy abroad: our vision for global britain means standing up for democracy and for human rights thats what we are doing in belarus.
The move by the british government marks the second time that measures have been imposed under the new human rights sanction regime, which is designed to highlight uks approach to diplomacy ahead of the countrys departure from the eu.
In july of this year, britain issued 49 sanctions to individuals and organisations implicated in human rights violations, including 20 saudi nationals associated with the death of washington post journalist jamal khashoggi.
Many of the sanctions are largely symbolic since they target people with few evident ties to the uk, such as top myanmar generals punished over military atrocities against rohingya muslims.
The eus proposed sanctions are more extensive and target about 40 people, but they require unanimity. cyprus has insisted it supports the measures in principle, but wants fellow bloc members to deliver on a pledge to take a tougher line against ankara over its eastern mediterranean energy exploration.
In 2016, the eu which then included the uk lifted sanctions on 170 people, including mr lukashenko, reflecting a modest improvement in political ties with minsk.