Millions have already been spent on redundancy payments to senior WA Police personnel, as the McGowan Government moves to re-tool the public sector.

WA Police say 12 senior executives have accepted voluntary redundancies, with total payouts to hit $3.2 million.

That comes on top of another $5.1 million in compensation paid to 18 departing senior bureaucrats, who were forced out by the amalgamation of departments.

Of the 12 WA Police redundancies, three positions were abolished while the rest of the duties will be passed down to lower-ranked employees.

But the over $8 million already paid out is just the start, with the WA Government saying it is committed to a full 20 per cent cut in senior public service staff.

No word has been given on the forecast cost of the public sector reforms, but says they will eventually lead to cost savings in the long run.

Opposition Leader Mike Nahan predicted the cost of payouts would top $25 million if 20 per cent of executives were culled.

Dr Nahan also criticised the WA premier and treasurer for taking time off amid public sector “chaos”, just 65 days before the state budget is handed down.

The Opposition leader and former treasurer said the premier and several ministers were on leave during the winter recess, leaving just Health Minister Roger Cook behind to be “minister for everything”.

“This is not any way to run a government, especially a government that's undertaking massive reform,” Dr Nahan told reporters on Tuesday.

“I would never have taken leave 65 days before the budget.

“At this stage, ministers would normally be working closely with their directors-general about their department's budget, however, I am receiving feedback that this is not happening either because ministers are away or because there have been so many changes at the executive level.”

Mr Wyatt posted on Twitter during Dr Nahan’s the press conference: “The budget is well underway and it's not easy cleaning up the mess of Treasurers Buswell, Barnett, Porter, Barnett, Buswell, Barnett and Nahan.”