A raft of international law firms have lined up to advise in the high-profile TNK-BP dispute, as some advisers fear straining UK/Russian relations could impact on the country's legal sector.

City players Linklaters, Lovells, Herbert Smith and SJ Berwin have joined the likes of New York leader Cravath Swaine & Moore and Russia's Egorov Puginsky Afanasiev & Partners in the proceedings, which took a dramatic twist last week when TNK-BP chief executive Robert Dudley left Russia to try and run the business from outside the country.

BP has turned to Linklaters and Egorov for advice with Linklaters' London litigation and arbitration partner Michael Bennett advising on the £181m tax case BP has brought against the four Russian oligarchs making up the Alfa-Access-Renova (AAR) consortium that owns the other half of the joint venture. The case looks set to go to arbitration in Sweden.

Egorov has been advising BP on Russian matters, including the bid to extend Dudley's visa to work in the country. Dudley – who has been struggling to retain his position as AAR reportedly attempts to oust him – and the management of the joint venture vehicle have turned to Herbert Smith, where Moscow corporate partner Robert Wittering (pictured) is leading the team. AAR, meanwhile, is using Lovells – including London partners Christopher Grierson and David Lyons – and SJ Berwin to handle UK and Moscow matters as well as Cravath. Clifford Chance is also understood to have a role in the case, while Sweden's Vinge could be brought in for AAR if the arbitration happens.

The case, which comes as the long-running $4bn (£2bn) dispute between two Russian businessmen for a 20% stake of aluminium giant RUSAL is set to be heard in the UK courts, is expected to put further pressure on Anglo-Russian relations and dent foreign investors' confidence in the region.

However, with so many firms involved in the case and the clients in the country both lucrative and litigious, few partners were willing to speak out publicly about the wider impact of the dispute.

Ashurst London-based corporate partner and co-head of the Russia and CIS group, Sergei Ostrovsky, said: "Of course it is not positive because it creates a feeling of uncertainty. But I do not think this case on its own will have wider ramifications for the existing investors in Russia, for many of whom things may be going perfectly well financially."

One magic circle partner with management responsibilities in the region said: "There is a danger in seeing the dispute as having wider implications. It is a dispute between two shareholders which could have taken place anywhere in the world."

However, White & Case's M&A partner Philipp Windemuth, who splits his time between Berlin and Moscow, was less certain. He said: "In the short term it has already caused a drop in the Russian stock markets. The long-term effect will depend upon how the Russian Government further manages its reaction to the dispute."