The image of the hard-up artist toiling away day and night for little or no reward is nothing new but research published on Monday may still surprise.

It shows that more than 70% of contemporary visual artists who took part in publicly funded exhibitions in the last three years received no fee. Almost as many are now saying no to galleries because they cannot afford to work for free.

The figures are published as part of a new campaign called Paying Artists, which is seeking a more equitable system.

Susan Jones, director of artists membership organisation a-n, said most people would be surprised that contemporary artists often "did not get a bean" for taking part in shows at publicly funded galleries.

She said the practice of not paying artists was now deeply entrenched in gallery culture "and presents a worrying trend".

Research suggests artists are £6,000 a year worse off, in real terms, than they were in 1997. "Artists … are not always thinking or talking about money. But we live in an expensive society, overheads have gone up for everybody and the research shows how staggeringly worse off artists are while at the same time more people are enjoying the visual arts and visiting galleries. There is an imbalance that needs redressing."

A-n represents 18,000 artists, from emerging talent to people nominated for the Turner prize. More than a 1,000 were surveyed revealing:

• 71% taking part in publicly funded exhibitions received no fee

• Of those, 59% did not get their expenses paid

• 63% have turned down gallery requests to exhibit because they cannot afford to work for nothing

• 72% of artists made less than £10,000 in a year from their art practice.

Jones said artists were at the frontline of the squeeze on already cash-strapped galleries, forced to make savings as levels of funding, nationally and locally, go down. "If you're short of money, where do you save it?"

The Paying Artists campaign was not a battle with galleries, she said. "There is a symbiotic relationship – artists need galleries and galleries need artists otherwise there's nothing for people to look at.

"Many curators are extraordinarily supportive of artists and really help their careers but the bottom line is 'everyone needs some money'."

The campaign is supported by galleries such as The Showroom in north-west London which gets 40% of its income from Arts Council England. Its programme has four shows a year which are new commissions from artists and it pays an average of £2,000 for each one.

One of those shows was printmaker Ciara Phillips who was nominated for this year's Turner Prize as a consequence.

The gallery's director, Emily Pethick, said she would like to be able pay more because the key thing with artists was time. "In order to have that time artists need to be paid. It's really important to make this issue of the artists' economy visible. There is a lot of cultural production in this country but the people who are paid the least within it are the artists. It really does need a big rethink."