Romson tells newsagency TT that she reacts against reports that "propaganda, or persuasion and marketing is used ahead of a referendum in another country".
She says it is a sensitive issue. "A fighter plane is not just any commodity. It is not Sweden as a country, but the private Gripen company selling the plane. How would Sweden have reacted if countries who want to sell nuclear power had been involved during our referendum?"
Romson also says she is not impressed by the weak response from government ministers to the reports that there is a campaign for this. "Yet again, this creates secrecy around the Gripen-affairs," she says.
The Left Party's Torbjörn Björnlund is also demanding that all Swedish activities top before the Swiss referendum.