A delay in plans to scrap prescription charges for chronically ill patients has been criticised by Welsh assembly members.

Draft legislation for the move has been passed with the support of the Liberal Democrats and Plaid Cymru and has been costed at £19 million.

However, Labour AMs have withdrawn the plan and replaced it with a law to end the £6 charge universally, a move that is estimated to cost £30 million.

The pledge, made by first minister Rhodri Morgan during May's elections, had been interpreted by some as a means of bribing the electorate.

Assembly members from the Labour benches welcomed the announcement despite 20 of their number, including health minister Jane Hutt, supporting the original bill.

"This project has been subsumed in to a bigger policy which will be of benefit to a greater number of people," said Aberavon AM Brian Gibbons.

However, opposition parties argued the change would adversely affect the seriously ill in Wales.

"The Labour Party say they will introduce free prescriptions for everyone but while they lay their plans, many of the people in most need must continue to choose between medicines and other priorities," said Kirsty Williams, the AM for Brecon and Radnorshire who introduced the first bill.

"The minister [Hutt] and her turncoat Labour colleagues voted for this piece of legislation and now they are simply tossing it away.

"People in Wales with long-term chronic illnesses will be desperately disappointed to learn that the Labour Party have backtracked on this commitment."