Rocking the boat The oligarch and the politicians

Oleg Deripaska was at the centre of “Yachtgate” in 2008 when Lord Mandelson and George Osborne both boarded his vessel, the 238ft Queen K, while on holiday in Corfu.

The two politicians were both guests of Nat Rothschild, the financier, as was Mr Deripaska.

Questions were raised about conflicts of interest for Lord Mandelson, who as EU trade commissioner was involved in setting aluminium tariffs. Mr Deripaska made his fortune from aluminium.

Mr Rothschild alleged that Mr Osborne had attempted to solicit a political donation from Mr Deripaska, an allegation both men denied.

Lord Mandelson had at least two dinners with Mr Deripaska in Moscow while he was trade commissioner, and according to Benjamin Wegg-prosser, his former aide, the two men had a friendship based on “jousts and arguments”.