A proposal to disqualify dishonest politicians from the Senedd is wholly unrealistic and could see the courts inundated with complaints, barristers warned.

The Criminal Bar Association, which represents practising members in Wales and England, criticised calls to create an offence of deliberate deception.

Jonathan Rees, a Welsh barrister, urged real caution before making any changes to the criminal law as he gave evidence to the Senedd’s standards committee.

He suggested the Welsh Parliament could instead expand the scope of the “tried-and-tested” offence of misconduct in a public office which is subject to important safeguards.

Mr Rees raised concerns about a model proposed by the Institute for Constitutional and Democratic Research, warning a new offence would put a huge burden on courts.

The think tank recommended disqualifying Senedd politicians and candidates from office for deliberate deception, to further the aim of restoring public trust in politics from record lows.

But Alex Greenwood, who practises regulatory and criminal law, warned the proposed model could infringe on longstanding rights under the European Convention on Human Rights.

Mr Rees added: “In many respects, it’s wholly unrealistic. It states that a key objective … is the need for swift justice. Well, the proposal they have then set out will not come anywhere near meeting that objective.”

The King’s Counsel pointed to examples including “fake claims” on chancellor Rachel Reeves’ CV and Labour’s manifesto commitment not to raise tax on working people.

He said: “We think it is entirely foreseeable that the courts … would simply be swamped, inundated with applications by voters of all political persuasions competing.”

Labour’s Lee Waters countered: “On the practicality point, that’s an argument for not bringing any more criminal sanctions in … I don’t deny the courts are swamped but I’m not sure if that should be the first basis on which we make law.”

Mr Waters said the paper’s model should not be treated as the last word, pointing out that it is only evidence to the committee rather than a firm Welsh Government proposal.

In July, the Welsh Government committed to introducing a ban before the next election.