Taxes should differentiate between different types of plastic bags, the Labour Party's spokesman on the environment, Leo Brincat insisted, criticising what he termed as the indiscriminate tax introduced in the budget on both conventional and biodegradable bags.

He said the government should clearly explain the direction it wanted to take. He said the Resources Ministry confirmed it did not know the precise volume of waste derived from plastic bags.

The Labour Party, Mr Brincat continued, was therefore questioning the credibility of such incentives as the eco tax on plastic bags when the government had not even compiled the necessary information to determine whether their use was declining.

He said the first eco contribution scheme, introduced with the aim of substantially reducing the use of plastic bags, had failed miserably. To add insult to injury, the government had now considerably raised the tax in its last budget.

Mr Brincat said it seemed like the government had done this without considering ways of making biodegradable bags more profitable.

"A tax system should, for example, have been introduced that distinguishes between different types of bags and that promotes a gradual phasing out of conventional plastic bags," Mr Brincat said.