A pre-inquest review will be held on Thursday into the death of a Russian spy Alexander Litvinenko who was poisoned with a radioactive substance in 2006.
Litvinenko, 43, was poisoned with polonium-210 while drinking tea at a meeting, allegedly with two former KGB contacts Andrei Lugovoy and Dmitry Kovtun - at the Millennium Hotel in London's Grosvenor Square in November 2006.
High Court Judge Sir Robert Owen has been appointed as an Assistant Deputy Coroner and will oversee Thursday's hearing. He is expected to give directions about "the conduct of the inquest".
British officials charged former KGB spy Lugovoy with his murder, but Russia has rejected the request for his extradition
Prosecutors named Lugovoy as the main suspect in the case. But he was later elected as a Russian MP, and a diplomatic rift developed with Moscow, which refused to send him to the UK for questioning.
Prime Minister David Cameron has said the issue - which he has discussed with President Vladimir Putin - still stands between Britain and Russia.
St Pancras coroner Dr Andrew Reid, who is currently suspended but presided over earlier inquest hearings, said the former KGB agent's inquest should have a broad scope and that the Metropolitan Police and intelligence agencies MI5 and MI6 should conduct further inquiries.
Alexander Litvinenko before taking the poison
Former justice secretary Kenneth Clarke wrote to Dr Shirley Radcliffe, the deputy Inner North London coroner, asking for cuts in the estimated £4 million bill of the inquest.
Mr Clarke wrote the letter after it was agreed that central government would cover the bill.