With Germany's national election campaign heating up, opposition chancellor candidate Edmund Stoiber was called Thursday to give evidence on June 4 to a special parliamentary committee investigating the country's long-running slush fund scandal.

The committee's decision to call Stoiber to appear before it came despite strong resistance to the move from the combined Christian Democrat Union-Christian Social Union (CDU-CSU) opposition.

Established in the wake of evidence of illegal donations being made to the CDU during the reign of Chancellor Helmut Kohl, the move to call Stoiber follows fresh allegations this week from one of the central figures in the scandal, the arms industry lobbyist, Karlheinz Schreiber.

Stoiber is also both Bavarian premier and leader of the CSU. Having fled to Canada to avoid tax evasion charges and other charges, Schreiber this week told an extraordinary hearing of the committee in Toronto that he had channelled donations totalling about two million marks to Stoiber's CSU, during 1991 and 1992.

After more than two years of deliberations, the committee, which is dominated by Germany's ruling Social Democrats (SPD) and their junior coalition partners, the Greens, said it plans to release its final report on June 6. The report would then be debated in parliament.

The committee said it also wanted to hear evidence from Max Strauss, the son of former Bavarian Premier Franz Josef Strauss on the CSU donation practices.

With Chancellor Gerhard Schroeder's SPD trailing the CDU-CSU in opinion polls, opposition members have attacked the committee's decision to call Stoiber as an attempt to raise questions about his background in the build up to the September 22 election.

At the height of revelations about the slush fund scandal, support for the conservative opposition parties plunged.

But more recently, a weak German economy and a fragile jobs market has swung public opinion away from the SPD and towards the CDU and their Bavarian-based associate party, the CSU.

With acknowledgement to Sapa.