Downing Street has refused to rule out inviting Sri Lanka to a First World War commemoration service despite an outcry from human-rights organisations.
No 10 said normal protocol should be followed for the event with Commonwealth heads of state in Glasgow.
Amnesty International Scotland have called on the Coalition to prevent the Sri Lankan Government from attending amid allegations of appalling abuse.
Asked about Sri Lanka, which is due to take over the chairmanship of the Commonwealth later this year, No 10 said: “The usual approach on invitations to members of the Commonwealth should be followed”.
The Sri Lankan Government has been accused of creating a climate of fear as well as sanctioning attacks on the media, judges, activists and political opponents.
David Cameron is already facing calls not to travel to the Commonwealth Heads of Government Meeting in the Sri Lankan capital Colombo in November.
However, the Coalition Government has insisted the Prime Minister will attend.
Downing Street said the UK Government would use the event to put pressure on the Sri Lankan Government over its human-rights record. There are signs of growing pressure on that position within the Coalition.
Earlier this week, Deputy Prime Minister Nick Clegg said he supported Mr Cameron’s stance, but warned Sri Lanka it would face the consequences if it did not address human-rights abuses.
LibDem deputy leader Simon Hughes is among those who have appealed to the Prime Minister to boycott the event.
The commemoration of the outbreak of the First World War in 1914 will be held just after the final day of next year’s Glasgow Commonwealth Games.
It will include a special service in Glasgow Cathedral, followed by a wreath-laying ceremony at the War Memorial. The event is designed to be a focal point of Commonwealth activities to mark the centenary and is expected to be attended by leaders from across the globe.
Glasgow’s Lord Provost Sadie Docherty, will lead the ceremony, remembering Britain’s role.
She has said: “I know this is something Glaswegians will want to be part of. They value their hard-won freedoms and are extremely proud of their city’s contribution.”
The possible inclusion of Sri Lanka, however, has triggered outrage from campaigners.
Amnesty International Scotland has urged the UK Government to consider whether it is appropriate to invite Sri Lanka to this event “in light of the level of recorded human-rights abuses”.
The Sri Lanka Campaign for Peace and Justice warned the country was preventing many of its people from commemorating their dead