The proposal, put forward by the nationalist For Fatherland and Freedom party, met with strong opposition from various lawmakers interviewed by the Russian-language Chas newspaper.
Russia's relations with its Baltic neighbor have been strained in the post-Soviet era by the Latvian government's policy toward Russian-speaking residents, which Moscow sees as discriminatory.
The paper quoted Vitaly Orlov of the Harmony Centre, a political alliance in parliament, as saying: "You can't ban any language. I, for example, often hear people from Latgale [an eastern region of Latvia] speak in Latgalian."
The deputy also referred to a lawmaker who often speaks to his colleagues in French. "It never occurred to me that you can ban a language," he said.
Alexander Golubov, of the Socialist Party, said: "This idea is completely stupid. It's unlikely parliament will support it. Parliament has enough work as it is. It's another pre-election move by this radical party."
The proposal will be considered by lawmakers next week.
As well as disputes over the rights of Russian-speakers in the EU country, another divisive issue in relations with Russia is Latvia's refusal to grant citizenship to many ethnic Russians, who make up around one-third of its 2.3-million population. Relations have also been strained by an unresolved border dispute.
