A Conservative-run council has been accused of reaching a “new low for diversity” with its all-male cabinet.
A team of seven men will be in charge at the Vale of Glamorgan, led by Tory councillor John Thomas.
The Electoral Reform Society (ERS) said newly-formed council cabinets in Wales were not reflecting the fact more than a quarter of councillors are women.
A Conservative spokesman pointed to the Vale’s female mayor and young deputy mayor as evidence of its diversity.
About 28% of councillors are women following elections on 4 May, the ERS said.
The proportion ranges from 42% in Swansea to 10% in Ynys Mon, where only three women were elected. However, Ynys Mon will be led by a woman – Llinos Medi, of Plaid Cymru.
So far, the Vale of Glamorgan is the only authority with an all-male cabinet.
The Conservatives said they had a lot of first-time councillors in the county without cabinet experience.
Mr Thomas, who takes over from a Labour-led administration, said: “The new cabinet brings a wealth of professional and political experience to the council and will provide the leadership needed to develop services fit for the 21st Century.”
A female mayor – Janice Charles – has been appointed. The mayor has ceremonial duties and presides over meetings, but does not have executive responsibilities for running the council.
ERS Cymru director Jess Blair said: “The Vale of Glamorgan council’s failure to have any women on their cabinet is a new low for diversity.
“We have serious concerns that other authorities across Wales are also failing to appropriately diversify their cabinets with all councils so far failing to be gender balanced.”
A spokesman for the Vale’s ruling Conservative group said: “We are proud to have returned on May 4th with a diverse and talented team of first-time councillors, many of whom will go on to be instrumental in shaping the future of the Vale of Glamorgan.
“In Janice Charles, the Vale of Glamorgan will have an excellent champion as mayor, supported ably by Leighton Rowlands – who we have appointed as the Vale’s first ever Youth Champion, and as the youngest deputy mayor in Vale history.
“We have ambitious and exciting plans for the Vale, and this will be an administration which works tirelessly to increase engagement with young people, to increase diversity and to attract new people into politics.”