In an interview with Dagens Nyheter vice-speaker Björn Söder says no one can be a member of the "Swedish nation" and at the same time the "Jewish nation" or the "Arabic nation." But such people can be Swedish citizens, despite not belonging to the nation, he says.
Björn Söder says his statement should not be taken to mean that he thinks people should be treated differently, but that the aim must be for immigrants who are not of the Swedish nation to abandon their original culture and identity and become part of the Swedish nation.
The Sweden Democrats say this will only be possible if immigration is sharply restricted, mostly from the countries seen as furthest from their definition of the "Swedish nation."
The Discrimination Ombudsman, Agneta Broberg, says this statement means there will be more unfair treatment for Sami, the indigenous people here, and other groups.
The head of the Sami Parliament's board, Håkan Jonsson, demands an explanation from Söder.
On Monday, Left Party politician Rossana Dinamarca and Liberal party MP Roger Haddad broke with Parliamentary tradition and attacked Söder during a debate.
Social Democrat parliamentary group leader Tomas Eneroth says Söder should consider resigning, since a speaker of Parliament should be able to represent all Swedish voters.
However, according to Parliamentary rules the deputy speakers have no obligations to be politically neutral when not acting for the speaker.