The Senedd has signed off on a 16 per cent budget increase, with the Welsh Parliament set to expand to accommodate an additional 36 politicians from 2026.

Members voted 31 to 13 to approve the Senedd Commission’s £83.8m budget for 2025/26, which includes an extra £11.6m for the reforms, public-sector pay and infrastructure.

Hefin David described next year’s spending plans for the commission – which is responsible for support services and the Senedd estate – as a transformational, step-change budget.

The Caerphilly Senedd member, who is the commissioner responsible for the budget, said the 16 per cent uplift will cover a 60 per cent increase in the size of the Senedd.

But the Conservatives criticised the “ballooning” costs, describing Senedd reform as the wrong priority while around one in five people in Wales are waiting for NHS treatment.

Leading a debate on 20 November, Dr David said the budget for the 12 months from April will address Senedd reform; the ‘Bay 2032’ project looking at offices as the Tŷ Hywel lease runs down; critical infrastructure projects; and a five per cent pay award for staff.

He said the £6.5m allocated to the reform programme includes costs for employing new staff, and reconfiguring the debating chamber and new members’ offices.

Dr David told the Senedd: “In these turbulent times strengthening a democracy is often a difficult but certainly noble endeavour.

“While I in no way devalue the objections of those opposed to reform, those members who have supported Senedd expansion have done so to build a stronger parliament for the people of Wales.”

Janet-Finch Saunders, the Conservative Senedd commissioner, said the budget reflects significant efforts to ensure effective management of public funds.

She told the Senedd that the costs compare favourably with the Scottish Parliament which is nearly £200,000 more expensive per member.

But she reiterated her party’s opposition to expansion, saying: “We still believe that these resources would be better allocated to essential public services, such as health care, education, our road infrastructure, social services – I could go on.”

Ms Finch-Saunders told the chamber that she had been inundated with messages from members of the public calling for a referendum of expansion.

Under the Senedd Cymru (Members and Elections) Act, the Welsh Parliament will grow from 60 to 96 members and adopt a new electoral system from 2026.

The legislation was passed in May, with a two-thirds supermajority voting in favour.