Eight of 15 government departments, including the Cabinet Office, are below the national average of 6 per cent for uptake of payroll giving among employees, according to figures from the Geared for Giving Campaign.
The campaign, launched in 2008 to encourage more employers to facilitate and promote payroll giving, obtained the information through Freedom of Information Act requests made in February and March.
In its payroll giving consultation document, the government said it recognised its responsibility as one of the country’s largest employers to "lead by example" on workplace giving.
The campaign said the replies showed that the Department for International Development had the lowest proportion of staff members signed up to the tax-free giving scheme, with 55 out of 1,397 employees, or 3.9 per cent.
The Cabinet Office, which includes the Office for Civil Society, has 89 employees out of 1,935, or 4.6 per cent, signed up to donate through payroll giving.
Other departments have far more employees signed up, including the Treasury, which is leading the consultation, with 109 out of 1,176 staff involved, or 9.3 per cent. The Department for Education is top with 490 out of 3,890, or 12.6 per cent, donating through their earnings.
Overall, from the 15 departments surveyed, 15,251 government employees out of 163,182, or 9.4 per cent, are signed up to payroll giving.
Peter O’Hara, managing director of Workplace Giving UK, the professional fundraising organisation that funds the campaign, said it was "unacceptable that so many government departments are not on a par with the national average.
"Given the real benefits to charities and tax efficiencies that workplace giving provides, we would like to see the government stay true to its word and set a real example," he said.
He said he hoped that the high-performing departments would share their success with others and encourage them to follow suit.
A Cabinet Office spokesman said: "We want to lead by example – we will continue to drive awareness and encourage participation across the civil service, in both this and volunteering. We expect to make further announcements in this area shortly."