The Welsh Government promised to introduce a law banning lying politicians before the next Senedd election after striking a last-minute deal to avert defeat.

Mick Antoniw, who is counsel general, the Welsh Government’s chief legal adviser, reached an agreement with Adam Price just before a key vote on creating an offence of deception.

Under the elections bill, Mr Price proposed a four-year disqualification for Senedd members, ministers or candidates found guilty of deliberate lying.

Mr Antoniw stopped short of supporting criminalisation as he invited the Senedd’s standards committee, which is holding an inquiry on accountability, to make proposals.

He said: “The Welsh Government will bring forward legislation before 2026 for the disqualification of members and candidates found guilty of deception through an independent judicial process.”

In return, Plaid Cymru’s 12 members and Rhys ab Owen, who sits as an independent, abstained – with Labour winning the vote to remove clause 64 from the bill, 26-13.

Mr Price said: “What has just been announced by the counsel general is truly historic, in fact it is globally pioneering.

“We now have a commitment from the government that our democracy will be the first – the first in the world to introduce a general prohibition on deliberate deception by politicians.”

Mr Price, who served as Plaid Cymru leader from 2018 to 2023, said a collapse in trust in politics poses an existential threat to democracies worldwide.

Labour’s Lee Waters said there is consensus across the chamber that deliberate lying undermines public trust in politics and needs to be rooted out.

Peter Fox gave the Conservatives’ backing for Mr Price’s plan.

James Evans sympathised with Mr Price’s proposal, saying he thought it would go some way to rebuilding public confidence in politicians.

But he cautioned the plan could do “real democratic damage” as he raised risks to parliamentary privilege – legal immunities which allow politicians to speak freely.

Mr Evans suggested Senedd members could face a flurry of defamation lawsuits.

The Tory MS for Brecon and Radnorshire told the Senedd: “I don’t think it is right that someone’s personal views could be challenged in court.”

Jane Dodds said political dishonesty is corroding public trust, adding: “Truth in our society is fragile and vulnerable. Our goal is straightforward: it is to stop politicians ... from calculated lying.

“That is an act that can have a deep, often traumatic consequence to people’s lives. And let’s be clear here: freedom of speech is not freedom to lie.”