Concerns about the growth of self-styled fitness clubs organised by the far right have prompted calls for action to counter misogynistic messaging targeted at young men and boys.

Campaigners want the UK government to recognise the danger presented by so-called “active clubs” – a loose movement imported from the US – and use moments such as a review of the school curriculum to challenge their ideology.

While it has often been careful to avoid direct calls to violence, the decentralised grouping has links to the international far right and has a specific focus on developing members’ fitness with a view to being able to fight.

Thousands of subscribers across Britain are signed up to accounts on Telegram, the encrypted messaging app.

White nationalism, fascist imagery as well as homophobic and misogynistic language feature heavily, while many of the same fitness groups’ Telegram channels have been posting attempts to stir up tensions after the deaths of three young girls in Southport.

A range of active club groups in the UK had upwards of 6,000 subscribers on Telegram while the latest version of a group dedicated to England had almost 1,600 subscribers, a BBC investigation reported this week.

Evidence seen by the Guardian indicates that members of equivalent clubs in the US have travelled to the UK in recent months.

The groups’ relative growth – researchers regard the true number of participants as being a fraction of the thousands of subscribers – comes as more overtly political British far-right groups such as Patriotic Alternative have struggled.