The English-only option in the Senedd's written record of proceedings undermines the institution's commitment to treating Welsh and English equally, an expert on bilingualism has said.
Dr Hywel Glyn Lewis said it facilitates treating Welsh "as if it did not exist".
A Senedd spokewoman said the bilingual, English and Welsh options reflect the languages' "equal status".
Only 16% of the words used in Senedd plenary meetings in 2019-20 were Welsh.
For many years the assembly, as it was then called, provided the record in a bilingual format, with the languages in parallel columns, with the language spoken on the left and the translation on the right.
The parliament now also provides the option of reading the record in English only or Welsh only - neither version makes clear whether it was the language spoken or a translation.
Dr Hywel Glyn Lewis, from the University of Wales Trinity Saint David, told BBC Wales that "seeing the two languages at least in parallel ensures linguistic equality".
"This can motivate individuals (who have little bilingual proficiency) to develop and extend their skills, even if they do so passively and unintentionally," he said.
He warned that "the effect of an alternative scheme where only English can be read while ignoring Welsh completely is to treat the language as if it did not exist; adopting a policy which, while allowing politicians to claim that the Welsh language is 'officially equal' and of equal status, means Welsh is less visual in status than English and consequently also has less of a psychological effect."
A spokewoman for the Senedd Commission, which runs the institution, said: "One of the Senedd's top priorities is to ensure that our work is transparent and accountable.
"In order to make the service as accessible as possible we offer everyone the option of using the Record bilingually or in one language of their choice, reflecting the equal status of our official languages."
According to data for 2019-20, 16% of the words used in the Senedd plenary meetings were Welsh, down from 20% in 2017-18.
In committee meetings, only 6% of contributions were in Welsh in 2019-20, compared to 8% in 2017-18.
Dr Lewis added that the use of Welsh in Senedd meetings and providing a bilingual record "can be a powerful influence on others to foster their bilingualism".
The Senedd spokeswoman added, "the Senedd is a bilingual organisation that treats both languages equally and encourages the use of Welsh as much as possible.
"There are a large number of services available to support and ensure that staff and members are comfortable in using the Welsh language and there is no time when the opportunity is not available to use both spoken and written Welsh."
While the contributions by Members of the Senedd in plenary meetings are translated for the record, committee transcripts include Welsh to English interpretation only.