Sweden's foreign minister says a British exit from the European Union could badly damage the 28-nation bloc.

Margot Wallstrom told the BBC in an interview broadcast Saturday that a vote to leave the European Union in the June 23 referendum could have a domino effect on other members, and lead to demands by member states for preferential treatment.

She says the "spill-over effect will be unfortunately felt, deeply felt."

Wallstrom says that Britain's vote will have consequences regardless of the result. A vote to leave may embolden other countries who may wish to abandon the Europe project while a vote to stay may encourage other countries to request "special treatment."