Two fuel duty rises next year will force people to cut back on food shopping and household goods, an AA/Populus survey has showed.
With the rises due to add 8p a litre to the price of petrol and diesel at the pumps, 18% of AA members said they would be cutting back on grocery shopping.
The poll of 16,647 members also showed that 23% will abandon or delay spending on household goods, home improvements and luxury items.
As many as 28% of 18-to-24-year-olds said they cut back on groceries and 36% would scrap plans to buy furniture, home entertainment and other household goods in the near future.
AA members in Wales look set to suffer most, with 22% cutting back on groceries and 27% on household and luxury goods. They are followed closely by drivers in the East Midlands, with 21% cutting back on groceries and 25% on household and luxury goods.
Overall, only 20% of AA members said they would be unaffected by the duty increases - 24% among top managers and professionals but falling to 15% among skilled and unskilled manual and service workers.
Almost two-thirds of those polled said they would cut back on car use if the fuel duty rises go ahead next year, rising to 68%-69% among unskilled workers and pensioners.
More significantly, 6% of AA members said they would have to sell or take a car off the road, rising to 8% among unskilled workers, pensioners and drivers in Northern Ireland.
One in five of the UK sample said they would have to downsize a car, while 6% will forgo their cars and switch to two wheels, with the figure for unskilled workers being 10%.
AA president Edmund King said: "Fuel duty contributes more than 5% to the total UK tax-take, including council tax and income tax. Governments tell us to drive less when they need us to drive more. So who really is car dependent? This survey shows that, if fuel duty increases go ahead next year, it will hit those who can least afford it."