Polling firm Sifo's June survey contradicts the results of a major Statistics Sweden (SCB) poll published on Thursday.
Where SCB pointed to an absolute parliamentary majority for the Mona Sahlin-led Red-Green opposition, Sifo puts the four-party governing Alliance in a 2.8 point lead.
“It's the first time since November  that the Alliance has surpassed the Red-Greens. It's a strong recovery,” said Toivo Sjörén at Sifo to newspaper Göteborgs-Posten.
The Alliance will however be concerned that the Centre Party and the Christian Democrats continue to hover perilously close to the 4 percent threshold required for parliamentary participation.
The poll results gave a boost to the Sweden Democrats: the far-right party would hold the balance of power should the Sifo results hold sway on election day in September.
Although the SCB poll is the largest of its kind, the Sifo results echo a trend recorded in recent weeks by several polling organizations. Analysts have attributed the discrepancy to the fact that many of the potential voters polled by SCB were approached before the left-green opposition presented a raft of joint policies in May, an event that precipitated a dip in support for the three-party coalition.
Sifo polled 1,910 prospective voters on their party preferences in interviews carried out from May 31st to June 10th.
Sifo poll results, June 2010 (changes since May 2010 in parentheses)
Moderate Party 32.9 (+2.0)
Centre Party 4.9 (-0.2)
Liberal Party 6.1 (-0.6)
Christian Democrats 4.5 (+1.0)
Total: 48.4 (Election 2006: 48.2)
Social Democrats 30.6 (-3.7)
Left Party 5.1 (+0.8)
Green Party 9.9 (-0.8)
Total: 45.6 (Election 2006: 46.1)
Sweden Democrats 4.3 (+0.8)
Others 1.7 (+0.7)