Nearly half of people who donate to charity say they are already giving all they can afford, according to a new survey commissioned by the Institute of Fundraising.
The poll of 1,999 people who had given to charity in the previous three months found that 43 per cent of people said they were already giving as much as they could.
Respondents to the survey, carried out by the polling company YouGov in late January and early February, said a pay rise was the main factor that would encourage them to donate more.
Only 8 per cent of respondents said a reduction in public spending would make them more likely to donate to charity.
Two-thirds said approaches on behalf of charities, including friends raising funds for charity, street fundraisers, TV appeals and mailshots, had prompted them to give money.
The research also found that women were more likely to give to charity than men. Two-thirds of women said they had donated in the previous three months, compared with 59 per cent of men.
The full report will be published later in the spring.
"In these tough economic times, charities are increasingly relying on public donations to support their vital causes, and skilled fundraisers are key to building good relationships with donors and making the ask," said Peter Lewis, chief executive of the IoF.
"It is also clear that charities need to effectively communicate how this money is going towards good causes, because any donation, no matter how modest, is vital right now."