Philipp Mißfelder, head of the Junge Union, told the Leipziger Volkszeitung that the middle road that the Christian Democrats (CDU) had been following was turning off conservative voters.
Amid dwindling support in the polls, Merkel is under intense pressure, with some conservative commentators recently speculating about whether she may be forced out.
The party had to show a clear, conservative direction and refuse to let the issues being pushed by the ascendant Greens party gain centre stage, Mißfelder said.
“We have to shift focus to our own themes, like economic competence, finance, family and education,” he said.
Ahead of the youth organisation's annual conference in Potsdam this weekend, at which both Merkel and Bavarian premier Horst Seehofer will be guests, Mißfelder also made it clear that he saw Guttenberg, who belongs to the Bavarian sister party of the CDU, the Christian Social Union, as the best hope for the future.
With his modern but clearly conservative orientation, Guttenberg was the “best political guarantee of survival for the union and defence against the Green zeitgeist.”
“Karl-Theodor zu Guttenberg, with his great credibility, appeals to many non-voters and former voters, so that in a very short time he has become an indispensable bearer of hope,” he said.
The theme of family will be the focus of the Junge Union conference this weekend.