Tory and Lib Dem leaders in the Welsh assembly have accused First Minister Rhodri Morgan of falsely claiming they backed plans to raise party whips' pay.
Rhodri Morgan wants whips' work recognised in their salaries
Nick Bourne and Mike German said Mr Morgan's assertion that they wanted to pay the four whips a total of £59,000 extra was "disgraceful".
Labour Assembly Member Carl Sargeant would be best off, with a £26,000 rise.
Mr Morgan's spokesperson said the letter was based on the "consensus" of three parties "as far as we knew it".
The job of whips is to organise their parties' business in the assembly and ensure AMs vote in line with their party's position.
A letter to Presiding Officer Dafydd Elis-Thomas, seen by the BBC, said there was "consensus" among the parties that whips should be paid an extra £1,000 per member of the group they represent.
Because Labour has 26 AMs in the chamber, this would boost the salary of its chief whip Mr Sargeant, the Alyn and Deeside AM, by £26,000.
AMs receive a basic salary of £46,496, so his total earnings would rise to just under £72,500.
Plaid Cymru's Chris Franks would receive an extra £15,000, Conservative William Graham £12,000 and Lib Dem Kirsty Williams £6,000, making her salary higher than that of her assembly group leader Mike German.
Such extra payments are made in neither the Scottish Parliament nor Northern Ireland assembly.
EXTRA THE WHIPS WOULD GET
Carl Sargeant, Lab:£26,000
Chris Franks, Plaid:£15,000
William Graham, Con: £12,000
Kirsty Williams, Lib Dem: £6,000
Mr Bourne and Mr German said the matter had never been discussed with them and that they did not support the plan.
They maintained that any decision should be left to an independent body which would be conducting a review of AMs salaries over the coming months.
Mr German said: "This smacks of a political fix. For Rhodri to say there is consensus between the parties is just not true.
"There has been no discussion with us, and as far as I understand none with the Conservatives either."
Mr Bourne said: "My gut instinct is that that has to be justified because it is a lot of public money".
"That is why I think it has got to be looked at externally," he added.
A paper prepared for the Assembly Commission, which runs the assembly and would pay any salary increases, warned that deciding on the matter before the investigation could harm the institution's image.
The paper stated: "Making a decision in advance of the review would appear to be a reputational risk in that the public perception of the assembly could be damaged by negative media reporting".
Mr Morgan's spokesperson said: "The 'consensus' view as far as we knew it, was that three of the four parties [Labour, Plaid Cymru and the Conservatives] agreed that there should be recognition of the work that the whips carry out in facilitating assembly business".
She continued: "Ultimately this is a matter for the commission to determine".
The commission meets on Wednesday morning.