A young councillor has spoken of being “screamed at relentlessly” at meetings amid concerns Welsh politics is dominated by older men.
Elyn Stephens, elected to Rhondda Cynon Taf council at 25, said she had been subject to “intimidation” because of her age.
Meanwhile, Jack Sargeant, youngest member of the Senedd, says politics is an “old boys’ club” in parts of Wales.
The Welsh Local Government Association said diversity was a “challenge”.
This year, about 70,000 16 and 17-year-olds will be allowed to vote for the first time in the Senedd elections.
BBC Wales research found however, the average age for councillors in Wales stands at 60, while in the Welsh Parliament it is 55.
Only 12 of Wales’ 22 local authorities said they had any elected councillors under the age of 30.
Mr Sargeant, who was voted into the Senedd three years ago aged 23, said there was “resistance” and “barriers” preventing young people from getting involved.
“I think we’ve done a lot of talking about accessible politics for a number of years now… but it takes action, the action of generally being kinder in politics,” he said.
Ms Stephens, now 29 and represents Ystrad on Rhondda Cynon Taf council, said she had faced intimidation from older councillors, mostly “down to age rather than being a woman”.
Since being elected, she has led a campaign to provide sanitary products for free in schools in her local authority, and eventually right across Wales.
“Without young people pushing for that policy it still wouldn’t exist, I’m sure of that,” she said.
“I’ve come across some challenging behaviour and there’s definitely been attempts at intimidation.
“There have been meetings where I’ve had a councillor in his second or third term screaming at me across the table relentlessly. I think it was just an attempt at intimidation to see how I would react, what I would do.”
Labour MS Mr Sargeant, said it was “not hidden” that among “some elected representatives” there is resistance to young people getting into politics.
“Let’s focus on that, because I think that’s perhaps one of the real barriers from entering,” he said.
“It takes someone quite brave to go out into the public arena and put themselves out there, and if elected representatives are acting in that way, how can we ask our members of the public to do any better?
“What I received during my election was: ‘You’re too young and how dare you speak up for this, what do you know?’
“That level of naivety, I think, from some, and perhaps a level of of being a bit scared that there’s someone with bright, energetic ideas ready to help.”
Aaron Wynne, a 24-year-old Plaid Cymru councillor in Conwy, said it can be like being back in primary school when listening to some arguments in the council chamber.
“I think sometimes party politics can get in the way of finding sensible answers to the problems people are facing,” he said.
“What I’d like, as a young person, would be to show that it is possible to work across the political spectrum to find a sensible answer to any problem society faces.”
And Mostyn Jones, a 28-year-old Conservative town councillor in Llanrwst, said more can be done to make it easier for young party members to stand for election.
“There is room for political parties to do more to help young people come forward,” he said.
“It can be extremely daunting when you know, for example, that a businessman is putting his name forward to represent the party in the same seat.
“It’s easy for a young person to be intimidated and immediately rule themselves out through concern that they don’t have enough experience and that they’re going to be eliminated at the first stage.”
In advance of the 2022 local elections, the WLGA has launched its “Be a Councillor” campaign, to “encourage more people from under-represented groups to stand for election in order to improve diversity in local democracy”.
A WLGA spokesman said: “The current Covid-19 pandemic has highlighted as never before the close relationship between councils and the people and communities they serve.
“Councillors and councils seek to represent and serve all sectors of their communities, however, council chambers in Wales do not always reflect the demographic characteristics of the population they serve.
“This is a challenge for all tiers of government and women and younger people are particularly under-represented.”