Opinion polls suggest that a majority of Icelanders will vote "no" on Saturday to the $5.3 billion deal to compensate Britain and the Netherlands for deposits lost in a collapsed Icelandic bank.
That is expected to complicate Iceland's effort to recover from a deep recession and a banking collapse.
The issue revolves around the payment of $3.5 billion to Britain and $1.8 billion to the Netherlands as compensation for funds that those governments paid out to around 340,000 of their nationals who had savings in the collapsed Internet bank Icesave.