The Welsh Liberal Democrats say they'll try to halt a planned £10,000 pay rise for Assembly Members by voting against the budget for running the Assembly.
AMs will be asked tomorrow to approve spending plans by the Assembly Commission which is in charge of services and staff at the Senedd in Cardiff Bay.
The Commission is proposing a budget of £52m for 2016-17 - an increase of £1.1m but a real terms cut when inflation is taken into consideration.
The budget includes £700,000 to cover the pay rise recommended by an independent Remuneration Board.
It's unusual for AMs to vote down the Commission's budget but the Lib Dems say it's the only way of stopping the controversial salary increase.
But the other three parties have rejected the Lib Dem call to join forces in voting against the budget.
Welsh Lib Dem leader Kirsty Williams said:
Kirsty Williams explained to me why she was making her call and why she believed it wouldn't undermine the independence of the Independent Remuneration Board.
The Lib Dems have failed to persuade the other parties to join them in voting against the Assembly Commission budget despite their own widespread public criticism of the proposed pay rise.
A spokesperson for Labour said to do so would be to create uncertainty for staff who work for the assembly 'for the sake of a headline.'
The Welsh Conservatives have also said they won't vote against the Assembly Commission budget and have criticised the Lib Dems for 'this desperate pursuit of a headline.'
A spokesperson for the party said:
Plaid Cymru has indicated that it too won't support the Lib Dem bid to vote down the overall Commission budget despite criticism of the pay rise from Plaid politicians. A party spokesperson said:
According to an Assembly Commission source, voting down the budget would in reality have no effect on the salaries paid to AMs and would create significant problems for funding services, staff and the extra expense incurred in an election year.
Concerns have also been voiced that it would also undermine the principle of independence that has been considered essential to allow the Independent Remuneration Board to act without interference from politicians.