The government, which has cut taxes and rolled back some aspects of the welfare state in its four years in power, has established a lead in opinion polls ahead of the Sept. 19 vote.
But the surveys have also shown it might not win a majority, particularly if the far-right, anti-immigration Sweden Democrats party wins its first ever seats.
This could lead to a hung parliament and a minority center-right government, which analysts have said would lead to short-term volatility on the markets.
A Sifo poll in newspaper Svenska Dagbladet released on Sunday gave the center-right, four-party government coalition 50.1 percent and the opposition center-left bloc 43.7 percent.
In that poll, the Sweden Democrats would not get into parliament.
A poll by Demoskop published by Expressen newspaper on Saturday suggested the government would win 50.5 percent and the opposition 44. That poll showed the government with a majority, but also showed the Sweden Democrats winning parliamentary seats with 4.2 percent of the vote.
The Sweden Democrats need to win at least four percent of the vote to enter parliament.
Several earlier polls have shown that the result of the Sweden Democrats winning seats would be a hung parliament, with the center-right being the biggest bloc, but with no majority in the 349-seat chamber.
A hung parliament is the one outcome that could upset markets in the short term, which otherwise see a victory for either the center-right or center-left blocs as broadly neutral for Sweden's public finances and growth prospects.
