The poll suggested that Merkel's Christian Democratic Union (CDU) and its Bavarian counterpart the Christian Social Union (CSU) would between them attract 39 percent of votes, Stern news magazine reported on Wednesday.
This is a not only a four-year high but also three percentage points up from last week, when the Union clocked up 36 percent.
Merkel's coalition with the Free Democratic Party (FDP) would score 44 percent, six percent ahead of the potential partnership between the Social Democratic Party (SDP) and Greens which together would poll 38 percent.
Experts at Forsa believe that Merkel's Union is becoming increasingly attractive to disappointed FDP voters, who in 2009 gave the party its best ever result with 14.6 percent.
Their frustration at the party's performance in government left it at times barely registering in some surveys, and it has only managed to climb back up to reach five percent with great difficulty. It now seems to be holding at five percent, the minimum needed for a party to enter parliament.
Now it seems those who voted FDP in the last election and deserted the party may be ready to vote for the conservatives in the next one – due in September 2013.
“Lots of voters who went liberal in the last election are turning back to the Union,” Forsa boss Manfred Güllner told Stern.
The conservatives seem to be able to hold onto their voters, he added. “Of the voters who voted for the Union in 2009, 78 percent have said they would be voting for them again, but only 25 percent of FDP voters are going to return to the liberals.”
The Social Democrats were at 26 percent, the Greens at 12 percent and far-left party the Linke at seven, all having dropped one percent since last week's poll. The Pirate Party remained steady at seven percent.