Peter Mandelson is set to begin a four-day trade trip to Moscow amid continued pressure on the Business Secretary to detail his meetings with a Russian billionaire.
The peer is visiting with a delegation of leading UK businessmen led by CBI Director General Richard Lambert, although aluminium magnate Oleg Deripaska is no longer among those he is scheduled to meet.
Summer visits by the then EU trade commissioner and shadow chancellor George Osborne to the oligarch's luxury yacht have led to questions about both the senior politicians' activities.
Mr Osborne spent much of last week fighting hotly-contested claims, made by the financier friend who arranged the meeting, that he had tried to secure a party donation from Mr Deripaska.
But the spotlight returned to Lord Mandelson when he admitted first meeting the businessman in 2004 - two years earlier than the first contacts mentioned in a previous press statement.
The EU's top trade official insisted that there had been "no political interference" from the commissioner when the EU cut aluminium tariffs - saving the Russian huge sums.
However, shadow business secretary Alan Duncan demanded a full explanation of the pair's dealings.
"All Lord Mandelson's so-called considered statements have been a carefully-crafted piece of the picture and only bit by bit -- drip by drip -- are we beginning to see the truth that he has been holding back.
"He should now make a full statement -- up to Westminster standards -- of all his interests and associations while an EU Commissioner," he told The Sunday Telegraph.
The twice-resigned Cabinet minister revealed his previous meetings with Mr Deripaska in a letter to The Times, in which he also pledged to ensure there would be no perceived conflicts of interest in his new role.
