Rules should be changed to avoid a repeat of the controversial barring of a Lib Dem from taking his seat in the Assembly at the last election, a Senedd committee has found.

John Dixon was prevented from taking his seat in 2011 after it was found that he, and Lib Dem colleague Aled Roberts, were members of public bodies that serving AMs couldn’t belong to.

Mr Dixon was still a member of the Care Council for Wales when he was elected, which was against advice given to candidates.

Both were disqualified following the election when the issue emerged, but Mr Roberts was reinstated after it emerged he had received out-of-date advice in Welsh.

Mr Dixon, then a Cardiff councillor, was replaced by Eluned Parrott, who was second on the South Wales Central regional list.

The report from the Constitutional and Legislative Affairs Committee has recommended the rules be changed to mean AMs should be required to stop being members of listed public bodies when they swear the oath or afformation of allegiance as an AM. Currently, AMs should not be members at the point they are nominated for election.

It said there are “complications” between two laws governing elections, leading to a conflict between advice given in the Government of Wales Act – which states candidates should be disqualified when elected – and a National Assembly Order in 2007 which says it is relevant at the point they are nominated.

The committee said the change would allow more people to stand for election, as candidates would be able to stand without giving up their jobs to do so. If the rule had been in place during the 2011 row, both would have taken their seats.

The report made 21 recommendations, including that the Welsh and UK Governments ask the Law Commission to investigate and report on options to change the law.

Chair of the committee David Melding said: “The committee recommends that disqualification from membership of the Assembly should take effect on taking the oath or affirmation of allegiance as an Assembly Member.

“We believe this is necessary to add clarity to the rules for potential candidates and is needed to avoid a repeat of the problems in 2011.

“We also believe that such a move could enable more people to stand for election as they could do so without potentially facing unemployment should they not be successful.”