The VAT differences north and south of the border are thought to have cost the taxpayer more than €700m.
The Finance Minister reportedly admitted that he made a mistake by increasing the rate here in October's budget, while Britain's VAT was slashed to just 15%.
Brian Lenihan made the comments at a private business lunch on Friday.
Director of Retail Ireland, Turlough Denehan, said the VAT rate is causing serious problems and needs to be reviewed as soon as possible.