Britain should warn Russia that the latest controversial conviction of oil tycoon Mikhail Khodorkovsky risks damaging trade links between the two countries, a senior Tory MP said.
Khodorkovsky, who was nearing the end of an eight-year sentence for tax fraud, was today found guilty of theft and money laundering charges and now faces several more years behind bars.
His first conviction was seen as a punishment for challenging Kremlin power, and prime minister Vladimir Putin also faces accusations of interfering in the latest legal action.
Richard Ottaway, who chairs the influential foreign affairs select committee, said it did not appear that the rule of law had been followed.
He encouraged the UK Government to take a tough stance over the case.
"I think we have got to make the point pretty forcefully that if they expect a good trading relationship between the two countries, we want to see a rule of law and a commercial code that we can all understand and follow," he told BBC Radio 4's The World at One.
He said it was not for Britain to get drawn into the "rights and wrongs" of the case, pointing to an apparent "power struggle going on inside the Kremlin over this particular case".
But he said the process raised serious concerns for Anglo-Russian commercial ties.
"I am very concerned about the way the court case has been conducted. The due process of law that we in the UK would recognise I don't think has been followed here," he said.
"The implications of that are actually quite serious for countries like Britain.
"Russia is a major player on the world stage. They are members of the Security Council of the United Nations.
"We have a lot of British businesses that invest in Russia, that deal in Russia, we have a lot of interaction with Russia and we do have to expect that the rule of law is followed, that there are standards and norms that we expect and parameters that we can operate by.
"Without those it shakes confidence in dealing with Russia in the long term."
A Foreign Office spokeswoman said the UK recognised the threat to trade relations and would continue to raise concerns with Moscow that the law "should be applied in a non-discriminatory and proportional way".
"We have been watching the trial closely," she said.
"We believe that Russia's people, and Russia's future, are best served by a judicial system properly independent of government or other outside interference; a system which administers justice consistently, transparently and objectively.
"This is also important in sustaining an environment in which investors can remain confident that they can do business, and that property and other rights are soundly protected.
"We welcome President Medvedev's focus on the need to strengthen the Rule of Law in Russia, including his focus on tackling corruption and promoting the independence of the judiciary.
"We, together with our EU partners, will continue to make clear to the Russian government our concerns that the law should be applied in a non-discriminatory and proportional way."