Leading opposition figures in Kazakhstan have urged Tony Blair to press for democratic reform in the oil-rich central Asian country or abandon his new role as adviser to the government.
Nursultan Nazarbayev, the authoritarian president of Kazakhstan, last month recruited the former UK prime minister to advise on economic reforms and presenting a better face to the west.
The two men are understood to have developed close ties after Mr Nazarbayev called at Downing Street during a state visit to the UK in 2001.
Officials in Astana said Mr Blair could provide what one called "priceless" advice and endorse oil-rich Kazakhstan's success as central Asia's most prosperous and stable country.
However, Kazakh opposition leaders said Mr Nazarbayev's objective in hiring such a high-profile foreign adviser was to burnish his international image and deflect attention from the country's deteriorating record on human rights.
Mukhtar Ablyazov, the former chairman of Kazakhstan's BTA bank who has waged a campaign against the government from exile in London, has written to Mr Blair warning he risks playing a destructive role in Kazakhstan unless he pushes Mr Nazarbayev to embrace democratic reforms.
"Attempts by western democracies to play along with the leaders of Iraq and Libya have ended up in multimillion dollar losses and hundreds of lives of young soldiers," says the letter, obtained by the FT.
"I hope that you have learned from these lessons and will either encourage Nazarbayev to change or resign from this spurious [advisory] role."
Mr Ablyazov is a controversial figure in Kazakhstan, where he is wanted on charges of embezzling billions of dollars during his tenure as chairman of BTA bank. BTA has hired Hogan Lovells, the UK law firm, to track down the missing assets and take its case against Mr Ablyazov to the High Court.
Mr Ablyazov, who has stepped up his opposition activities since fleeing Kazakhstan in 2009, is suing the government for allegedly expropriating BTA bank.
Bolat Abilov, the co-chairman of the social democratic party Azat, one of the country's biggest legal opposition groupings, said he had told Mr Blair that it was impossible to give meaningful economic advice in Kazakhstan without addressing the country's political problems.
"I have written to him as a member of the opposition to ask for a meeting to discuss the situation in Kazakhstan and ensure he gets an objective picture of what goes on here," he told the Financial Times.
Neither Mr Ablyazov nor Mr Abilov has received replies from Mr Blair.
Rights groups have urged Mr Blair to focus on human rights when advising Kazakhstan, rather than polishing the country's image.
Mr Nazarbayev wields sweeping powers in Kazakhstan, where the judiciary is not fully independent and law enforcers frequently harass critics of the regime.
"Repressive tactics so obviously on display in Kazakhstan have no place in a country boasting the fastest growing economy in central Asia," said Rachel Derber, deputy director of Europe and central Asia at Human Rights Watch.
"People advising Kazakhstan should begin with the rule of law and basic human rights." A spokesman for Mr Blair refused to comment