It would be “almost impossible” to keep the Senedd running if the Welsh government fails to pass its budget, the institution’s presiding officer has warned.

Elin Jones suggested the salaries of politicians in Cardiff Bay could be in jeopardy if that happened.

There are currently questions over how ministers will get their spending plans through if Labour fails to win this month’s by-election in Caerphilly.

Failure to pass the Welsh government’s budget would see a cut to the Senedd’s own budget.

The Senedd Commission, which is responsible for the day-to-day running of the institution, has said it needs a £19m (21%) uplift to its budget for 2026-27, in large part to cover the salaries and costs of the extra 36 Members of the Senedd (MSs) who will be elected in May as the Senedd expands from 60 MSs to 96.

If its plans are approved by MSs the Senedd’s budget will be rolled into the Welsh government’s 2026-27 budget motion, which would also then require the backing of a majority of Cardiff Bay politicians.

If the government failed to win that vote, the Senedd Commission’s own budget would be cut to 95% of its 2025-26 value.

That would leave the commission with £79.6m instead of the £102.3m it is currently seeking to help fund the newly-expanded Senedd as well as costs relating to the election itself including winding-up payments for MSs leaving the Senedd.

First Minister Eluned Morgan has already acknowledged it will be “tricky” for her government to pass its budget if Labour does not win the by-election later this month, leaving Labour needing the support of two opposition politicians in the Senedd.

Facing questions from the finance committee on Wednesday, Elin Jones said that heading into a normal year a budget set at 95% of the current year’s value would be “possibly manageable”.

However, given the significant budget increase the commission says it needs for next year’s “one-off situation”, the cut would be “an almost impossible ask for the running of the Senedd”, she said.

On the possible ramifications of such a cut, Jones added: “We haven’t even gone there is how I would say at the moment.”

“It would be so difficult to think about what that would mean both for commission staff and the numbers of commission staff and dare I suggest the payment of salaries of Senedd members ourselves, or whoever they may be, who are returned.”

The commission’s spending plans for 2026-27 include an assumed 5% pay rise for MSs, which would take a backbench politician’s basic annual salary to £80,199.