By Michael Buchanan
BBC Washington correspondent
A US television company is planning to run a film attacking Democratic presidential nominee John Kerry just days before the election.
John Kerry was a Vietnam veteran who later turned against the war
Sinclair TV Group's programmes reach almost a quarter of US homes.
Its move is highly unusual and may breach federal regulations requiring stations to give equal time to major candidates in an election campaign.
The 45-minute film criticises John Kerry's opposition to the Vietnam war in the early 1970s.
In the documentary, Stolen Honor, Wounds That Never Heal, former prisoners-of-war say that Mr Kerry's claims that American soldiers were committing atrocities led to their captors treating them more harshly, and extended the length of the conflict.
The Sinclair TV Group, whose executives have given tens of thousands of dollars to President George W Bush's re-election campaign, have revealed plans to show the film later this month, followed by a panel discussion to which they say Senator Kerry will be invited.
This is the latest attack in a vitriolic campaign to discredit Mr Kerry
The decision to air the documentary on the 62 stations that Sinclair either owns or supplies programmes for has been criticised not only by the Kerry campaign but also by media analysts, who say showing the one-sided film so close to the election is unfair.
This argument over the role of the media in the presidential race is just the latest in this year's heated campaign.
Michael Moore's anti-Bush film Fahrenheit 9/11 outraged conservatives, who say it distorts the president's White House record.
And just recently CBS News had to apologise to Mr Bush for broadcasting a programme that was based on now-discredited documents.