The advertisers' trade body also believes that introducing 30-second spots for political parties would create an array of difficulties in regulating ads and would drive up the cost of airtime for marketers.
ISBA has made its views known in its own submission to the Electoral Commission, which is looking at ways of making politics more attractive to younger people.
"There is a clear need for a debate about how our democratic process can be supported by the communication of political messages,
said ISBA director-general Malcolm Earnshaw. "The vast majority of advertisers would oppose paid-for political advertising on television. Given the undoubted controversy which would surround political ad campaigns, the subsequent negative publicity could rub off onto brands and advertisers."
Last week, Marketing reported that Peter Mandelson opposed the IPA's views about the reform of PPBs because "the public is fed up with soundbite politics".
Since last year's general election campaign, there has been a limit on political parties' ad spend, restricting them to a maximum of £20m in the year before an election.