Linklaters has been criticised by the Foreign Affairs Select Committee investigating Russian financial interests in the UK, for refusing to discuss its role on the London listing of Russian energy company En+ Group.

The magic circle firm advised the banks on the initial public offering (IPO) of En+, which was formerly controlled by Russian oligarch Oleg Deripaska, last November, which raised about £1bn.

The listing was backed by Russian investment bank VTB Capital and state-owned Russian bank Gazprombank, both of which have been subject to US sanctions since 2014. This April, Deripaska himself was also placed on a list of sanctioned individuals by the US, and he has since ceded control of En+.

In the wake of the poisoning of former Russian spy Sergei Skripal on UK soil earlier this year, a parliamentary committee led by Tom Tugendhat MP was set up to investigate Russian influence in the UK, and today (21 May) the committee published its final report – Moscow's Gold: Russian Corruption in the UK.

As part of the inquiry, Linklaters was asked to appear before the committee "to explain their involvement in the flotation of En+ and to give their assessment of the regulatory framework that enabled the flotation to take place", but refused, according to the report.

The report states: "We regret their unwillingness to engage with our inquiry and must leave others to judge whether their work at 'the forefront of financial, corporate and commercial developments in Russia' has left them so entwined in the corruption of the Kremlin and its supporters that they are no longer able to meet the standards expected of a UK-regulated law firm."

The report argues that the En+ float should have "attracted the attention" of UK regulators and describes it as an example of the "inconsistency" in the UK's approach to the Russian regime.

A spokesperson for Linklaters said: "We are very surprised and concerned at the passing criticism of Linklaters in the report. We reject any suggestion based solely on the fact that we – like dozens of other international firms – operate in a particular market, that our services may somehow involve the firm in corruption, state-related or otherwise.

"As a leading global law firm, Linklaters adheres to the highest standards of business conduct, ensuring we comply with applicable laws and professional rules, including with respect to anti-bribery and corruption, anti-money laundering and sanctions."

As well as his interests in En+, Deripaska is also a director of Russian aluminum company Rusal, with the inquiry report stating that "his proximity to the Kremlin" is "well known". En+, which has a controlling interest in Rusal, announced last week that Deripaska was resigning as a director of the company and would also not seek re-election as a director of Rusal.

In April, partners told Legal Week they were sceptical of claims by Conservative MP and Foreign Affairs Select Committee chair Tugendhat that lawyers should consider the "moral decisions" they take when they engage with Russian clients.