The Welsh Language Board is due to be scrapped by 2007

The WLB is due to be abolished and its duties brought under the control of the assembly government by 2007.

Opposition parties want the process to be postponed for clarification of the plans and may act to strip the first minister of his authority over the WLB.

An assembly government spokesperson said the threat was "hypocrisy".

Quangos scrapped

The publicly-funded WLB was set up in 1993 under the terms of the Welsh Language Act.

Its main function is to promote and facilitate the use of the Welsh language.

Last year, First Minister Rhodri Morgan announced that the WLB would be one of several publicly-funded unelected bodies - or quangos - which would be scrapped and their duties brought under the control of the assembly government.

Opposition parties have claimed there have been problems in the preparatory work to scrap the WLB.

Earlier this month, a motion by opposition parties - who have a majority in the assembly - was passed, calling on the assembly government to freeze the plans while any difficulties were resolved.

'Ignore vote'

The assembly government has decided to continue with the process and Plaid Cymru has warned it may take steps to strip the first minister of his authority over the WLB.

Plaid's assembly leader, Ieuan Wyn Jones, said: "Because of the way the original act was written, they (the assembly government) can ignore that vote in the assembly and they can carry on all the preparatory work necessary to abolish the board.

"We believe that is wrong - they have to respect the political will of the assembly and that's why we are taking this step by taking away the powers the government has to do that work."

The leader of the Liberal Democrats in the assembly, Mike German, said that what Plaid Cymru's proposal was an "interesting idea" but added that he was confident the assembly government would pay heed to the opposition parties' request.

'Democratise Wales'

The Conservative leader in the assembly, Nick Bourne, added that he would have to hold discussions with the Tory group in the assembly and then with other opposition leaders.

Responding to the threat, Welsh Culture Minister, Alun Pugh, told BBC Wales' Dragon's Eye programme: "I think this is particularly extraordinary because Plaid Cymru have been consistent all along.

"They voted to work with us to democratise Wales to have greater public accountability of elected ministers, and for them to turn around at this stage and to say we want to wreck the constitutional settlement is quite extraordinary."

A Welsh Assembly Government spokesperson added: "It is hypocrisy of the highest order but it is not at all surprising.

"Ieuan Wyn Jones has said very clearly that he wants to see the end of the quango state by 2008 - and yet it's clear that he want to set up another quango for the Welsh Language Board".