Leading veterans of causes including LGBTQ+ rights and the anti-apartheid struggle, as well as conservative causes such as hunting, have criticised government plans to broaden the definition of extremism. They include the Labour peer Peter Hain – who took direct action against white-only South African sports tours in the 1960s and 70s – and Tim Bonner, the Countryside Alliance chief executive and one of the organisers of the 2002 march for rural communities. Downing Street is already facing a backlash from Conservative MPs and peers over moves in response to what Rishi Sunak describes as the threat of “mob rule” – but which even some Tories believe could encompass causes such as anti-abortion activism. Michael Gove, the communities secretary, is expected to publish plans this week that would allow the government and other public bodies to cut off links to groups identified as “extremist”. The definition will reportedly apply to those who seek to “undermine” the UK’s “institutions or values”. Hain said: “I think it’s an appalling direction to go down and it could probably have been applied to the suffragettes in their day, who were equally vilified, spat at, hated and treated very badly by the police and the authorities.” Hain, a former Labour cabinet minister, was 19 in 1969 when he confronted white South Africans on sporting tours of the UK to highlight the brutal injustice of apartheid. The Stop the Seventy Tour campaign, of which he was chair, ruined the all-white South African rugby tour and forced the cancellation of the 1970 cricket tour to Britain. “At that time people like me and others involved were hated and attacked and vilified, and it’s only more recently that those who thought that way have come to understand why we needed to do what we did. But we would have been targeted under this new approach to a definition of extremism.” Organisations such as the Muslim Council of Britain are among those that could be affected by the non-statutory move to block groups from funding or accessing venues if they are regarded as promoting an ideology that undermines “British values”. However, the latest critic of the reported plans is the Countryside Alliance, a campaign group with deep conservative links, whose chief executive told the Guardian of its concerns. “We are concerned that defining extremism as something as woolly as ‘undermining fundamental British values’ will become an excuse to crack down on any opinion which isn’t shared by a majority of the population,” said Tim Bonner. “Real British values fundamentally respect minority views and do not seek to silence them,” added Bonner. He was a free range egg producer in Devon at the time of the 2002 Liberty and Livelihood march in London – the biggest rural protest the UK has seen, and who was originally hired by the Countryside Alliance for a few weeks to help promote the demonstration. Four hundred thousand people were reported by the BBC to have taken part in the march, which had a central focus around opposition to a ban on hunting with hounds. Another critic of the plans is Peter Tatchell, the LGBTQ+ and human rights campaigner, who said: “The Tories seem to be suggesting that groups undermining ‘British values’ should be declared extremist and subject to new restrictions. But what are British values? “They used to be slavery, colonialism, homophobic discrimination and the denial of votes to women and working-class people. British values are still contentious today.” “Broadening the definition of extremism risks criminalising peaceful protests by legitimate groups like hunt saboteurs and Greenpeace. It would have criminalised direct action groups like the Gay Liberation Front in the 1970s and the LGBT+ rights group OutRage! in the 1990s. My attempted citizen’s arrest of the Zimbabwean dictator Robert Mugabe, and my ambush of Tony Blair’s motorcade in protest at the Iraq war, would likely fall foul of the new extremist definition that some Tories want to see.” The UK already has some of the harshest anti-protest laws of any western democracy, added Tatchell, who claimed that the plan to crack down echoed Vladimir Putin’s Russia. Other opposition has come from the National Secular Society (NSS), which said that the proposed definition could “label secularists and republicans as extremists” on the basis of their opposition to institutions such as the Church of England and the monarchy. “There are grave risks that a more expansive definition would lead to the labelling of legitimate political opinions, advocacy for social change, or dissenting voices as ‘extremist’,” the NSS chief executive, Stephen Evans, wrote in a blog. • This article was amended on 11 March 2024 because an earlier version omitted “and republicans” from the quote from the National Secular Society.