"We consider this to be a political statement, that Sweden is a multicultural society," Sweden Democrat press secretary Martin Kinnunen told The Local on Thursday.
The church service, to be held in Stockholm Cathedral at 3pm, will be led by the dean Åke Bonnier with Växjö bishop Jon-Olof Johansson, rabbi David Lazar and imam Othman Al Tawalbeh in attendance.
Sweden Democrat leader Jimmie Åkesson has responded to the multi-faith make up of the service and outlined his objections in an opinion article published in the Svenska Dagbladet daily on Wednesday.
"It is Christianity and its values that form the basis on which our society rests, although this seems to be difficult for many to accept," Åkesson wrote.
Åkesson continued to underline however that he considered the service to be an important part of the ceremonies leading up to the opening of the parliament by King Carl XVI Gustaf later in the day.
"The ceremony is for me an important manifestation of our shared heritage, the thoughts and beliefs that have built our country."
The Sweden Democrats grabbed the headlines at last year's ecumenical service when they stormed out when bishop Eva Brunne argued that xenophobia and racism "is not worthy of a democracy like ours".
But despite the Sweden Democrats objections to this year's service, Jimmie Åkesson plans to attend. Party colleague Erik Almqvist has however decided to boycott the occasion.
"There is no requirement from the party's side for MPs to attend. The decision is left up to them," Martin Kinnunen told The Local.
This is not the first time that the traditional Riksdag opening service has been multi-faith with the practice first observed in 2007 and then repeated in 2009.