The RAC has joined those calling on the Chancellor not to increase IPT in his Autumn Statement this November.
With the organisation's 2016 Report on Motoring showing the price of car insurance is drivers' number one cost-of-motoring concern, the RAC says recent IPT increases have had a substantial impact on household finances.
RAC Insurance director Mark Godfrey said: "The cost of insurance has never ranked as highly among motorists' concerns in previous years' research for the Report on Motoring as it has this year, and neither has it featured as prominently in motorists' assessment of increased motoring costs.
"Insurance premiums are going up faster than they have at any other time in the last five years. We don't want annual increases in IPT to become a feature of the chancellor's Budget and Autumn Statement. We would like an assurance from the Treasury that IPT will not be increased any further."
The report says a major contributor to rising premiums is the problem of spurious whiplash injury claims. Criticising government for its slowness to address the issue, Godfrey said: "We do not believe that the government's proposals last autumn will necessarily get to the heart of the issue and nearly 10 months later we are no further forward as the promised industry consultation to address the issue has not yet begun. We need the government to push forward on consultation to get to a concrete set of changes that will deliver a reduction in such personal injury claims."
The RAC is also calling on government to make young drivers' telematics 'black box' car insurance policies exempt from IPT. The policies can reduce young drivers' premiums, which are among the highest of all age groups and present the biggest barrier to owning and running a car after passing their test.