By Jonny Hogg
BBC News, Antananarivo
Didier Ratsiraka was forced into exile in France in 2002
One of four political parties in Madagascar has pulled out of the talks to end a political crisis.
The team of former President Didier Ratsiraka said it was not possible to hold peaceful polls and constructive dialogue in the current climate.
The move came shortly after the UN said significant progress had been made in finding a way to end the instability.
The Indian Ocean saw former President Mark Ravalomanana driven from power in a military-backed takeover in March.
Hours after an unlikely breakthrough in negotiations, the decision of one of the political parties to pull out is a more predictable turn of events.
It is also a timely reminder of the problems still facing mediators as they try to find an exit to this bitter and complex political dispute.
In a hand-written fax Didier Ratsiraka, who was forced into exile in France following the country's last political crisis in 2002, said his delegation was suspending its involvement until there was an amnesty for all his supporters who were found guilty of politically-related crimes at that time.
He also condemned the current transitional authorities' decision earlier this week to set up - without consultation - a military council to push through army reforms.
In reality, this can be seen as political posturing from a movement that had become virtually obsolete until this latest crisis erupted and reopened old wounds.
Nonetheless, Mr Ratsiraka's decision to walk out may set a precedent for others to do likewise and could seriously diminish the goodwill that has helped drive the talks until now.