By Michael Nienaber
BERLIN (Reuters) - German Chancellor Angela Merkel's Christian Democrats (CDU) argued on Sunday over whether they should return to a more conservative agenda once she steps down as party chair as contenders to succeed her gear up for the leadership race.
Support for their Social Democrats (SPD) coalition partner meanwhile hit a record low, according to a poll published hours before senior members of both the CDU and the SPD were due to discuss the parties' future courses on Sunday in closed-door meetings.
Merkel announced last week that she would step down as CDU party leader in December, ending an era of nearly two decades in which she shifted the party gradually from the right to the centre. [nL8N1XB5JB] [nL8N1X926U]
Her decision followed two regional votes in which Merkel's centre-right bloc and the left-leaning SPD suffered their worst election results in decades while the ecologist Greens and the far-right Alternative for Germany (AfD) gained support.
Health Minister Jens Spahn, one of the three contenders to replace Merkel as party leader, said the CDU had watered down its profile by becoming too centrist in the past years.
"Parties must differ from another again more strongly," Spahn told Welt am Sonntag newspaper. "The way we view people and society is fundamentally different from the one of the Social Democrats," he added.
Spahn is one of the fiercest critics of Merkel's decision in 2015 to welcome more than a million refugees, mainly Muslims from war zones in the Middle East.
CDU deputy chair Armin Laschet warned against moving the CDU more to the right. "I'm convinced that such a policy shift would be wrong," Laschet told Sueddeutsche Zeitung daily. The CDU should stick to its centrist course, he added.
The candidate most likely to stand for a continuation of Merkel's centrist course is CDU party secretary general Annegret Kramp-Karrenbauer. [nL8N1XA5OP]
The third candidate is Friedrich Merz who would stand for a shift towards the low-tax, business-friendly right-wing conservatism that Merkel has pushed into the background.
Ahead of the separate meetings of senior SPD and CDU members, SPD deputy chair Ralf Stegner said his party would not remain in the coalition "at any price".
"If the coalition does not drastically and rapidly change its work mode and image, it cannot and will not last," he said.
The SPD was Merkel's coalition partner in her first term from 2005-2009, in her third from 2013-2017 and now again in her fourth and final ruling coalition. The SPD has been weakened by Merkel's centrist course and a more right-wing CDU could make the centre-left party more attractive to moderate voters.
A Forsa poll for RTL/n-tv broadcasters showed on Sunday that support for the SPD plunged to a record low of 13 percent while Merkel's CDU/CSU bloc rose to 27 percent.
The pro-immigration Greens jumped to 24 percent to become the second-strongest party, the poll showed. The AfD fell to 13 percent while the pro-business Free Democrats (FDP) and the party The Left both stood at 9 percent.
The fragmentation of the political landscape in Germany means that only the CDU/CSU and the Greens would currently be able to form a ruling coalition consisting of two blocs if the government collapsed and fresh election would be called.
(Reporting by Michael Nienaber; Editing by Raissa Kasolowsky)