Welsh mental health charity Hafal has complained that the design of the new Welsh Assembly building stops campaigners getting access to elected representatives.
The Senedd was officially opened by the Queen on 1 March. But John Abbott, campaigns manager for Hafal, who attends the assembly each week, said it had become inaccessible.
"Although the Senedd cuts a dramatic figure on the skyline, its use of glass around the debating chamber doesn't mean that proceedings will be transparent," Abbott said.
A spokeswoman for Disability Wales said: "In the old Assembly Building there was a 'milling area', where you could just as likely bump into Rhodri Morgan, the first minister, or Brian Gibbons, the health minister. That mixing has gone."