The companies are said to fear that a chewing gum tax would set a precedent that could be adopted by other countries.
The tax was first proposed seven years ago, when the then Irish environment minister, Martin Cullen, called for a five cents levy (2.5p) on packs to help fund cleaning up discarded gum. The tax could be as successful in reducing litter as the plastic bag levy, he said.
The government backed down after Wrigley, which holds almost 90% of the Irish market, called on the then US ambassador to Ireland, James Kenny, to lobby against it. Wrigley agreed to donate funds to a public awareness campaign against gum litter.
That agreement has now ended and Wrigley and Cadbury have submitted a new offer to government, said to be worth 9m over three years.
Irish Environment Minister John Gormley is set to decide whether to introduce the tax or not. He has previously campaigned in favour of one.