JULIA Gillard says small businesses hit by carbon tax power price hikes should pass costs on to consumers, who are getting compensation.

But companies in some sectors have questioned the Prime Minister's advice, saying they simply cannot lift prices.

One apple and pear grower said its electricity bills now had a "carbon charge" attached that was more than 15 per cent for one packing plant, but the supermarkets it supplies won't accept price rises in a competitive market. More carbon tax concerns have been raised by small business owners after a Daily Telegraph survey revealed some retailers are starting to feel the pinch.

The survey found many businesses were not passing costs through to consumers despite being hit by carbon tax-related power price hikes.

In parliament, Liberal MP Sharman Stone asked Ms Gillard about Victorian pear and apple grower Geoffrey Thompson Holdings, which has specific carbon tax components added to its July bills, totalling $23,000.

A power bill for one of the company's packing plants has gone up 15 per cent from the carbon tax charge alone.

Ms Gillard told parliament that businesses such as this could pass those costs through.

"That small business is dealing with consumers that have received tax cuts, family payment increases and pension increases because our anticipation is that small businesses would pass those modest price impacts on," she said.

But Geoffrey Thompson Holdings managing director Garry Parker said that was not realistic because the company supplied major supermarket chains with fruit -- and they would not accept price hikes.

"We will have to look at ways of taking cost out of the business, we will look at staffing and other areas," he said.