The Revenue collected a 18.8m from plastic bag purchases on behalf of the Environment Fund in 2006, but the amount of money available next year could increase even further now that the department has raised the charge per plastic bag by 47% to 22 cent, the maximum level allowable under current legislation.

If Irish consumers continue to use the bags at the same per capita rate as last year, the annual take will jump to 23.2m this year and as high as 27.6m in 2008 . . . approximately the same amount generated in 2006 by the normally more lucrative 20 per tonne landfill levy.

When the bag levy increase was announced in February, then minister for the environment Dick Roche said he expected the change to be nearly revenue neutral, raising less than 1m extra per year. However, that estimate was predicated on achieving a reduction in per capita bag use to below 2002 levels . . . the year the levy was introduced. Last year bag use crept up to 30 bags per person, continuing an upward trend from a low of 22 per person at the end of 2002.

But as the levy has reduced in consumer impact, it has correspondingly fattened the department's coffers, as revenue from bags has nearly doubled in just five years. This has, in turn, expanded the Environment Fund, a "ring-fenced" pool of money the department uses for various environmental initiatives from the local to the international level. It's biggest expenditure in 2005, the last year of published accounts, was local authority enforcement initiatives, which accounted for almost 9m of the 42m spent.

Not everyone is happy with the fund's good fortune, however.

Donal Buckley, Ibec's environment spokesman, said it had transformed from a capital fund to a "slush fund" for current spending, including UN subsriptions, salaries and grants for a range of projects.

The terms of the Waste Management Act of 2001 grant the minister wide discretion for the use of the fund.