Britain is facing a diplomatic rift with Kazakhstan, a key trading partner, over attempts by a leading Kazakh pro-democracy campaigner to seek political asylum from the British government.
Tensions have risen after Mukhtar Ablyazov, the founder of the Democratic Choice party that campaigns for economic and political reform in Kazakhstan, fled to Britain claiming that he was the victim of persecution by the country's ruler, President Nursultan Nazarbayev.
Mr Ablyazov, a banker and free market advocate, claims he was tortured after being jailed for six years and has applied to the Home Office for political asylum. The Kazakh authorities have rejected Mr Ablyazov's allegations and accused him of defrauding the state-owned BTA bank of an estimated £185 million.
The Kazakhs are lobbying Foreign Office ministers not to grant him asylum, which they say could jeopardise Britain's ties with Kazakhstan.
The Foreign Office regards Kazakhstan's support for the Afghan military campaign as important. Its role has assumed greater significance following the unrest in neighbouring Kyrgyzstan, the location of a key Nato airbase used to supply troops in Afghanistan.
But it is Britain's trade ties with Kazakhstan that most concerns ministers. Its vast, untapped energy and mineral reserves means that Britain is among the country's top five investors. Its burgeoning wealth was recently illustrated when the president's son-in-law bought Prince Andrew's Sunninghill Park estate near Ascot, Berkshire, for £15 million, £3 million above the asking price.
The Kazakh government has warned it will punish British firms by awarding lucrative contracts to China if Mr Ablyazov is granted asylum.
Mr Ablyazov is unrepentant. He said: "I am the biggest obstacle to the government's attempts to maintain absolute power over the country, and the regime wants to remove that obstacle."