Berlin, June 11 : Germany's ruling conservative union was gaining voters' favour and was clearly ahead of the second-placed Greens, according to a Politbarometer survey published by the public broadcaster ZDF. After a historical low in polls, the Christian Democratic Union/Christian Social Union(CDU/CSU) gained four percentage points compared to the last survey almost three weeks ago and reached 28 per cent, while the Green Party lost three percentage points and only reached 22 per cent, according to the survey issued on Thursday. Germany is heading for federal elections in September, reports Xinhua news agency. Chancellor Angela Merkel had already announced in 2018 that she would not run for office again after four consecutive terms. Germans' opinions on who would be a suitable chancellor also shifted. After scoring an approval rating of 43 per cent in May, only 28 per cent believed that Green Party leader Annalena Baerbock was suitable as chancellor, according to the survey. CDU leader Armin Laschet was seen by 43 per cent as ready for the chancellorship, a plus of six percentage points. Of the three candidates, Minister of Finance and Vice Chancellor Olaf Scholz (SPD) was in the lead, with 48 per cent considering him suitable for the chancellorship. /IANS