Boris Johnson has suggested extremism rules developed to tackle domestic terrorism could be applied to anti-foxhunting activists.
Mr Johnson told a pro-hunting group that activists who disrupt their events could face rules developed by the Government's Commission for Countering Extremism.
The Commission is considering the rise of far right, islamic and other kinds of extremism.
Mr Johnson made the suggestion in answer to a question from the Countryside Alliance during his successful leadership campaign.
The group say they asked him: "Will you commit to implementing measures to counter animal rights extremism, including any relevant recommendations from the Government’s Commission for Countering Extremism, which is due to report this summer?"
In reply, Mr Johnson said: "While I am committed to protecting animal welfare, I will not tolerate extremism, intimidation and abuse irrespective of the motives that drive it."
According to the Farmer's Guardian, he added: "I will consider any recommendations that come from the Commission [for Countering Extremism].”
When he was MP for Henley in the early 2000s, Mr Johnson repeatedly voted against a ban on foxhunting.
Later, when he was Mayor of London, he suggested introducing foxhunting in the Capital, after his cat was mauled by a fox.
He said: "This will cause massive unpopularity but I don’t care.”
But his partner, Carrie Symonds is an outspoken defender of conservation and animal rights.
