"This is going to be a real nail-biter. It could stay uncertain all the way until Wednesday," said Christian Democrat leader Ebba Busch.
According to a forecast by public broadcaster SVT, which is based on votes actually counted, it is essentially a neck-and-neck race between the blocs with nearly 70 percent of the votes tallied.
In the forecast, the opposition takes 49.4 percent compared to the governing bloc's 49.0 percent. Measured in seats, that leaves a razor-thin single-seat margin in favour of the centre-left: 175 to 174.
Just a few thousand votes separate the blocs.
"Every single vote must be counted. We aren't taking anything for granted in either direction," said Ebba Busch.
Over at the Liberal party headquarters, there were cheers as the party registered 5.4 percent in the projection. This comes after trailing around the 2 percent mark in the opinion polls for a long time, facing the risk of getting knocked out of parliament altogether.
"It's a historic comeback," said Liberal party leader Simona Mohamsson.
The Social Democrats stand at 27.9 percent and look to be heading towards their worst general election performance in modern history, should the figures hold.
In her election night speech, the Social Democrat leader noted how extremely tight things are between the blocs.
"And that means that regardless of how the final election result turns out, there is good reason to seek a new spirit of cooperation in Swedish politics," said Magdalena Andersson.
"But right now, we are in the lead. And if this holds, Sweden will get a new government."
The Left Party, the Centre Party, and the Green Party are all faring better in the forecast than in the 2022 election, standing at 8.3 percent, 7.1 percent, and 6.1 percent respectively.
"We have done everything we can to say goodbye to Tidö," said Left Party leader Nooshi Dadgostar, adding:
"But the situation remains uncertain for the opposition. We still don't know which side will govern Sweden for the coming four years."
Among the Tidö parties, hope remains alive for continuing in government for another four years.
In the projection, the Moderate Party stands at 19.9 percent, which is slightly higher than in the 2022 election. That would also mean retaining their spot as the second-largest party in parliament.
"This election result could lead to a complicated government formation. Where it ends up remains to be seen. It might take time, but we are in no hurry," said Moderate Party leader Ulf Kristersson.
The Sweden Democrats are losing ground for the first time in a general election, landing at 17.5 percent. Party leader Jimmie Åkesson nevertheless claimed they are "winners of the campaign".
"There are so many more people in our country now who don't feel awkward saying that they are a Sweden Democrat. On the contrary, people are proud," he said in his speech.
The Christian Democrats look set to make gains compared to 2022, securing 6.2 percent of the votes.