By Rachel Harvey
BBC South East Asia Correspondent, Bangkok
**A special United Nations Human Rights representative is in Burma for the start of a planned five day trip.**Ahead of what will be his third visit to the country since being appointed, Tomas Ojea Quintana, said Burma was facing a critical year.
Elections are due to be held sometime in 2010, for the first time in two decades.
Mr Quintana’s visit comes after the release on Saturday of a leading pro democracy campaigner.
Tin Oo, had been detained for almost seven years.
During his trip, Mr Quintana is expected to meet several ministers in the military government.
Detainee’s release
But he has not been granted an audience with the man who makes all key decisions in Burma - General Than Shwe.
The UN envoy is also likely to hold talks with opposition figures, and visit Rangoon’s notorious Insein prison.
He has not yet received a response to his request to meet the detained pro democracy leader, Aung San Suu Kyi.
The release of political prisoners is one of the main items on Mr Quintana’s agenda.
It is perhaps no coincidence then that a high profile detainee won his freedom just ahead of the UN envoy’s arrival.
Tin Oo, who is 82 years old, is deputy head of the National League for Democracy (NLD) - the party led by Ms Suu Kyi.
The Burmese leadership is adept at giving hints of progress on reform when international attention is focussed in its direction.
But it is worth noting that Tin Oo was at the end of his latest period of detention and as such his release does not represent a major concession on the part of the government.