ABC, CNN, CBS, Fox News, NBC and The Associated Press sued Ohio Secretary of State Kenneth Blackwell over a policy that would prevent exit polling within 100ft of a voting station.

The organisations have formed a consortium to collect exit-polling data.

The news organisations said the prohibition hindered their ability to gather information about the political process and violated constitutional guarantees of free speech. They contend exit-poll reporters were allowed access within 100ft of polls in the March primary.

Blackwell's spokesman, Carlo LoParo, cited increased media interest in the November election.

Anticipating a crush of voters and media on Tuesday, Blackwell told county boards of election to enforce a state law barring anyone except voters, election officials, challengers and witnesses from inside the 100ft limit, LoParo said.