Prime Minister Fredrik Reinfeldt's Alliance has been performing badly for months and over the summer it appeared extremely unlikely that his government could get re-elected.
But as The Local reported on Sunday, fewer Swedes are planning to vote against the Alliance than a week ago and support for the Social Democrat-led opposition is dropping.
However, just how much the Red-Green lead has narrowed varies widely according to different opinion polls.
Sunday's survey by Novus put it at 8.6 percentage points but another survey released over the weekend suggested an even smaller gap of 4.5 percentage points, down from 7.3 points a week earlier and around 10 percent a month ago.
It suggests that an extra 135,000 votes for the Alliance could put them neck-and-neck with the Red-Greens, indicating that the election result could be much closer than many had previously speculated.
Sweden allows its citizens to cast their ballots in ahead of polling day in some parts of the country, but a fall in advance voting also appears to suggest that many voters remain undecided.
According to Sweden's Election Authority website, 881,364 advance votes had been recorded by Monday lunchtime, compared with 912,156 a week before the election in 2010.
There is also speculation that turnout could be lower than in previous years.
Political commentator Dr Stig-Björn Ljunggren told The Local he believes the final outcome won't be too surprising.
"It is very unlikely that there will be such a dramatic change that the Social Democrats don't end up in government," he said on Monday.
But he argued that it was plausible that Fredrik Reinfeldt might attempt to stay in power if the gap between the Alliance and the Red-Greens continues to narrow.
"There are a lot of people speculating that the Prime Minister could seek help from the Sweden Democrats," he added.
"However everyone who knows him will tell you he hates everything they stand for, so I think that is very unlikely."
Dr Ljunggren said he believed there were several factors that could influence the election's outcome during the final week of campaigning:
- A political scandal involving any of the party leaders or top candidates
- Russia flexing its muscles further in Ukraine. Voters are more likely to select a sitting government during a international crisis
- Unexpected new policy announcements on key election issues such as healthcare, unemployment or immigration
On Sunday Prime Minister Fredrik Reinfeldt said that he was still "completely convinced that we can still change people".
He told reporters "a lot of people have indicated that they're still uncertain, and in that sense it's an open race".
"I will fight to do that all the way until the polling booths close," he added.