The background is media reporting on everything from Kristersson's wife Birgitta Ed's activities at Fållökna, to the renovation of the Sager Palace and the construction of a chicken farm in Harpsund.
Time and again it has been revealed that private interests, family relationships and personal networks have come too close to the exercise of public power, says Anders Ygeman (S) at a press conference.
He also points out that Kristersson took part in the government's decision to grant 12 million kronor to the Teach for Sweden foundation, at the same time as his sister-in-law was a board member of the foundation.
Foreign Trade Minister Benjamin Dousa (M) calls the move a "desperate smear campaign".
"The Swedish people do not want an American election campaign. They want a little normality, where we talk politics - not people," he writes.
