In a Saturday opinion piece for newspaper Dagens Nyheter, the Social Democrat prime minister Stefan Löfven wrote that he "will never act in a way that would give a Neo-fascist, single-issue party power over the country's development".
Löfven was referring to the Sweden Democrats, a party which he claims "does not respect people's differences or Sweden's democratic institutions".
Löfven also called for more cooperation between the centre-left and centre-right parties and a move away from the bloc politics that has been cemented in Sweden in recent years.
Löfven's remarks come just a day after Minister for Finance Magdalena Andersson called the Sweden Democrats a "Neo-fascist little party".
In an interview with news agency TT, acting Sweden Democrat leader Mattias Karlsson called Andersson's remark "ignorant, rude and undignified".
On Wednesday, the government - a Social Democrat-Green Party coalition - called for a new election after the Sweden Democrats voted for the centre-right opposition's budget.
The new election will be officially called on December 29th and is due to be held on March 22nd.