The Foreign and Commonwealth Office said it was advising against all but essential travel to Iraq because of a declining security situation.
Dozens of people were killed in attacks in predominately Shiite areas of Baghdad last week
The FCO warning said no travel advisories were in place for the semiautonomous Kurdish north, which has been relatively shielded from most of the violence in Iraq.
Officials recommended avoiding any demonstrations tied to the elections.
"Although the vast majority of election rallies are expected to pass off without incident, there have been violent incidents in some cases," a statement said.
The government pointed to tensions along the northern Iraqi border with Turkey as a source of concern. Last week, the militant Kurdistan Workers' Party said it was backing out of a peace deal with the Turkish government, accusing Ankara officials of failing to live up to their end of the bargain.
"Shelling in the border areas with Turkey and Iran in the Kurdistan region still occurs," the FCO stated. "Turkish security forces have carried out ai strikes and incursions into the border areas of Kurdistan, targeting the Kurdistan Workers' Party."