BERLIN, Sept 10 (Reuters) - The general secretary of German Chancellor Angela Merkel"s conservatives has pressed their rival Social Democrats" (SPD) chancellor candidate, Olaf Scholz, to explain himself over an investigation of his Finance Ministry by prosecutors. Prosecutors raided the finance and justice ministries on Thursday as part of an investigation into the government"s anti-money laundering agency, putting a spotlight on Germany"s failings in tackling financial crime. The raids come at a pivotal moment for Scholz, who opinion polls suggest has a good chance of becoming German chancellor in national elections on Sept. 26. "There are a great many questions that the SPD candidate for chancellor must answer," Christian Democratic Union (CDU) General Paul Ziemiak told news magazine Der Spiegel. "He must explain himself immediately." Scholz is SPD finance minister in Merkel"s ruling "grand coalition" with her conservatives. The probe into the Financial Intelligence Unit, an agency of the finance ministry under Scholz, is looking at whether it was told to ignore warnings of suspect payments to Africa. Asked by Reuters on the margins of a meeting of European finance ministers whether the raid on his ministry just ahead OF the election were a coincidence, Scholz said: "There can be no speculation on this question, so I am not going to do that." Merkel, in power since 2005, plans to stand down after the election. Armin Laschet, the chancellor candidate for Merkel"s CDU/CSU conservative bloc, is failing to resonate with voters worried about climate change, immigration and the COVID-19 pandemic. A Forschungsgruppe Wahlen poll published on Friday put support for the SPD at 25%, ahead of the CDU/CSU bloc on 22%, the Greens on 17%. The liberal Free Democrats (FDP) and far-right Alternative for Germany (AfD) were both on 11% and the far-left Linke on 6%.