GERMAN CHANCELLOR Angela Merkel has come under pressure to address the role of the Christian Democratic Union's (CDU) East German wing in supporting the socialist regime for nearly four decades.
The Ost-CDU was one of several "bloc parties" that survived by voting with the ruling Socialist Unity Party (SED) and allowing itself to be rolled out whenever the de-facto one-party state wanted to demonstrate its "democratic", multi-party credentials.
After unification in 1990, Helmut Kohl's CDU absorbed the Ost-CDU with little discussion.
Now, two decades on, eastern rank-and-file members are demanding a full examination of the Ost-CDU's past, including the party's defence of the Berlin Wall.
The timing couldn't be worse, with next year's 20th anniversary of the fall of the wall coinciding with the next general election.
CDU leaders are afraid of being accused of hypocrisy for airbrushing its own past while attacking the Social Democrats (SPD) for flirting with the Left Party, a successor organisation to the SED.
The debate returned to the agenda after Saxon state premier Stanislaw Tillich was forced to admit being more involved in the activities of the Ost-CDU than he had previously admitted.
"It's not a particularly honourable chapter of my biography and today I would decide differently," he wrote in a five-page statement.
"The Ost-CDU was part of the SED system. It helped support the state apparatus. That is the historical truth." A local CDU wing in the eastern city of Halle lodged a motion for today's party conference, calling for a full historical debate and describing Ost-CDU officials as the "henchmen and dogsbodies" of the SED.
Party leaders in Berlin rewrote the motion to state that the CDU was "forcibly neutralised by the SED [though] played a part in the totalitarian regime".
Irritated eastern CDU members complain the rewritten motion stifles honest debate by overshooting the original target and opening the door to the kind of witch-hunt they wanted to avoid.
The whole debate puts Dr Merkel in a delicate position. Like no other leading figure in the CDU, her political biography has been shaped by the party's approach to its recent past.
Raised in East German Brandenburg, she joined the CDU in 1990 but saw her attempt to become a state party leader a year later blocked by an Ost-CDU old boys' network. She eventually rose through the party ranks in the neighbouring state of Mecklenburg Vorpommern, but only after winning the support of former Ost-CDU grandees.