Russia's lower house of parliament voted unanimously on Tuesday to ban what authorities cast as pernicious propaganda for a child-free way of life, hoping to boost a faltering birth rate.

Official data released in September put the birth rate at its lowest in a quarter of a century while mortality rates are up as Moscow's war in Ukraine rages on. The Kremlin called the figures "catastrophic for the future of the nation".

President Vladimir Putin, who has cast Russia as a bastion of "traditional values" locked in an existential struggle with a decadent West, has encouraged women to have at least three children, saying that will help secure the future of Russians. There are already financial and other incentives.

The law, expected to be swiftly approved by the upper house of parliament and Putin, joins other restrictions on free expression including a ban on content deemed to promote "non-traditional lifestyles" such as same-sex relationships or gender fluidity, as well as on dissenting accounts of the conflict in Ukraine.

Authors of "child-free propaganda" will be subject to fines of up to 400,000 roubles ($4,100) for individuals, twice that amount for officials, and up to 5 million roubles ($51,000) for legal entities.

Some 599,600 children were born in Russia in the first half of 2024, which is 16,000 fewer than in the first half of 2023 and the lowest since 1999. The number of deaths jumped by 49,000. However, immigration jumped by 20%.