Ivory Coast’s former first lady Simone Gbagbo goes on trial Tuesday for crimes against humanity, but rights groups acting as plaintiffs in the case have pulled out, blasting the proceedings as flawed.

The wife of ex president Laurent Gbagbo has already been handed a 20-year jail sentence for “attacking state authority” over her role in post-election violence in 2010 that left more than 3,000 people dead.

Accused of involvement in rights abuses against supporters of her husband’s rival Alassane Ouattara to keep Gbagbo in the presidency, she faces allegations of crimes against prisoners of war, crimes against the civilian population and crimes against humanity.

But on Monday three rights groups, representing nearly 250 victims, said they would refuse to take part in the trial of the woman once known as the “Iron Lady” because of doubts over its “credibility”.

“Our lawyers have not had access to all stages of the procedures — how can they defend their case?” the head of one of the groups, the Ivorian League of Human Rights, told AFP.

Pierre Kouame Adjoumani said the trial lacked “relevance”, adding that Simone Gbagbo “is accused of crimes against humanity, something she could have only done through an organised group — so why is only she being judged?”

The trial is taking place in Ivory Coast’s commercial hub Abidjan, where the 66-year-old former first lady is being held.

It opens just five days after the Supreme Court rejected her final appeal against the 20-year sentence she was handed last year in her first trial.

Ivory Coast, the world’s top cocoa producer, suffered months of bloodshed after Laurent Gbagbo and his supporters refused to accept defeat to Ouattara in a 2010 election.

The violence was ultimately halted by an international military intervention under a UN mandate, led by former colonial power France, and the Gbagbos were arrested in April 2011.

Ouattara won a second presidential term in October in the nation’s first peaceful vote for more than a decade.

Laurent Gbagbo is currently on trial for crimes against humanity at the International Criminal Court (ICC) in The Hague.

The ICC also wanted to prosecute his wife and issued a warrant for her arrest, but Ivorian authorities refused to hand her over, saying she would face a fair trial at home.

The decision was seen as a snub to the ICC, with Ouattara saying he would “not send any more Ivorians” to The Hague, insisting his country has an “operational justice system”.

But the rights groups that pulled out of the trial on Monday complained that the initial investigation into Simone Gbagbo’s crimes was rushed and her first trial failed to establish her personal role in the violence.

Global body Human Rights Watch also complained that the Ouattara government has yet to carry out urgently-needed legal reforms, including a witness protection programme.

The president has also faced accusations that Simone Gbagbo’s trial is a sign that his government only intends to prosecute crimes by pro-Gbagbo forces in the conflict, charges he rejects.

Human Rights Watch said the trial could be a “pivotal moment” for justice in Ivory Coast, a country yearning for stability following several years of civil war from 2002 that split the mainly Christian south and the largely Muslim north.

“However, for the trial to be meaningful to victims, it must be credible, fair, and followed by other trials that target high-level rights abusers from both sides of the 2010-2011 post-election crisis,” the group warned.