YANGON, (Reuters) – A court in army-ruled Myanmar  sentenced opposition leader Aung San Suu Kyi to 18 months in  detention, a verdict that drew condemnation abroad and will  keep her off the political stage ahead of next year’s  elections.

The court handed down a three-year prison term for  violation of an internal security law on Tuesday. But that was  immediately halved on the orders of the military government,  which said the 64-year-old Nobel peace laureate could serve the  time in her Yangon home.

Myanmar’s home minister, Major-General Muang Oo, told the  court moments after the verdict it had taken into account that  Suu Kyi was the daughter of Myanmar independence hero Aung San  as well as “the need to preserve community peace and  tranquillity” as the country prepares for multiparty elections  next year.

The verdict drew criticism from leaders around the world.  Britain’s Prime Minister Gordon Brown called it “monstrous.”  French President Nicolas Sarkozy said it was “brutal and  unjust.”

The U.S. State Department spokesman called the charges  against Suu Kyi “spurious” and President Barack Obama said the  conviction violates universal principles of human rights. Obama  also called for Suu Kyi’s immediate release.

The 27-country European Union is preparing sanctions  against Myanmar, also known as Burma, that include restricting  trade with state-owned firms and barring top junta officials  from entering the bloc, Sweden said.

Sarkozy said the measures “should particularly target the  resources it profits directly from — wood and ruby mining.”