The three candidates hoping to be Germany's next chancellor stayed quiet on Tuesday amid wide-ranging plagiarism accusations concerning their own books.
Well-known researcher and Austrian academic Stefan Weber on Monday said that an examination of recent publications by the three candidates - and in particular Green Party candidate Annalena Baerbock - had revealed dozens of problematic passages.
Baerbock's book "Jetzt" ("Now"), published this year, contained at least 100 plagiarized fragments and probably many more than that, Weber said in a blog post accompanying his research.
In conservative Armin Laschet's book "Die Aufsteigerrepublik" ("The Achievers' Republic") from 2009, Weber notes 17 problematic passages.
When it comes to Social Democrat Olaf Scholz's "Hoffnungsland" ("Land of Hope") from 2017, Weber records three plagiarized fragments.
Weber said the case of Baerbock was exceptional.
"The result is shocking ... The text is a patchwork from somewhere else," he wrote on his blog.
Even worse for the Greens' candidate, Weber says the uncited sources include publications by political rivals: the conservative CDU/CSU bloc, as well as "a scientist close to the Social Democrats and a book by an entrepreneur close to the [pro-business] Free Democrats."
Baerbock has conceded making mistakes in the book after previous plagiarism accusations from Weber, and her publishers have promised a fuller explanation of the sources used in her book. The Greens have accused Weber of trying to tarnish her reputation.
Neither Baerbock nor the other candidates have responded to Weber's latest findings.
A leading opinion poll released on Tuesday showed the CDU/CSU alliance gaining a bit of ground that had been recently lost.
In the Forsa survey for RTL/ntv stations, the conservatives gained 2 percentage points during the previous week, to land at 21 per cent.
Scholz's Social Democrats, who have seen a surge of support in recent weeks, stayed steady at 25 per cent.
The other parties did not any change either - with the exception of the business-friendly Free Democrats, which lost 2 percentage points and are now on par with the far-right Alternative for Germany (AfD).
If the September 26 election were to be held today, the Greens could, according to the survey, expect 17 per cent of the vote and the hard-left Die Linke party 6 per cent.
According to the survey, one in four voters has not yet decided for whom to cast their ballot, or does not plan to vote at all.