Pollster INSA recorded further declines of half-a-percent for parties within Merkel's governing coalition on Tuesday in results published by the daily newspaper "Bild."

The right-wing Alternative for Germany (AfD) remained on 15 percent, with the ecologist Greens stable on 13 percent - fresh from their recent regional win in the southwestern German state of Baden-Württemberg.

INSA placed the AfD just four percent behind the 19 percent recorded for Sigmar Gabriel's center-left Social Democrats (SPD). The worst ever general election result for Germany's oldest mainstream left-of-center party was 23 percent in 2009 - typically the party would expect results between 30 and 40 percent of the vote in past decades, if not higher.

Merkel's bloc, comprising her Christian Democrats and allied Bavarian Christian Social Union (CSU), and Gabriel's SPD formed Germany's current governing coalition after September 2013 elections. Back then, they secured a combined 67.2 percent of the vote.

'Hard' confrontation needed

Germany's Christian Democrat Interior Minister Thomas de Maiziere said the AfD's rise to the right of Merkel's bloc amounted to a damaging situation that required a frank but fact-based confrontation with the populists.

Bild quoted Bavarian premier and CSU chairman Horst Seehofer as saying during a meeting of his party's leadership on Monday that there were "forces" within Merkel's CDU who regarded the CSU as a "faulty construct" of the early post-war years.

Since 1949, starting with Germany's first post-war chancellor, Konrad Adenauer, the CSU and CDU have maintained a joint grouping within the federal parliament. The CDU agrees not to run for offices in Bavaria, and the CSU pledges not to leave that state's confines.

If Sunday was election day?

INSA had asked survey participants who would they vote for, assuming that a federal election had been held last Sunday.

The liberal Free Democrats (FDP) garnered 8 percent, placing them well above the 5-percent threshold needed to enter parliament. The FDP fell short of this hurdle in 2013, as did the AfD.

The Left party scored 9.5 percent as it held its annual conference in the eastern city of Magdeburg and debated ways to counter the AfD's rise.

Two regional elections pending

"We must stop it," said Left party deputy chairperson Sahra Wagenknecht, referring to two regional assembly elections due in September in Berlin and Germany's northeastern state of Mecklenburg-Western Pomerania.

"It is a warning sign that the AfD has become the strongest party in Saxony-Anhalt and Baden-Württemberg among the unemployed and workers," said Left co-leader Bernd Riexinger, referring to two recent elections in German federal states.

"We must visit the social flashpoints; we must make ourselves useful for the people," said Riexinger, reiterating the Left's claim to being the advocate of social justice.

Political scientists say the AfD's bid to become the party for "ordinary people" places it in direct collision with the Left which since 1989 has appealed in eastern Germany to the perceived "losers" of German reunification.

ipj/msh (Reuters, dpa, AFP)