Theresa May, the Home Secretary, unveiled plans last month for so-called Extremism Disruption Orders, which would allow judges to ban people deemed extremists from broadcasting, protesting in certain places or even posting messages on Facebook or Twitter without permission.

Mrs May outlined the proposal in a speech at the Tory party conference in which she spoke about the threat from the so-called Islamic State – also known as Isis and Isil – and the Nigerian Islamist movement Boko Haram.

But George Osborne, the Chancellor, has made clear in a letter to constituents that the aim of the orders would be to “eliminate extremism in all its forms” and that they would be used to curtail the activities of those who “spread hate but do not break laws”.

He explained that that the new orders, which will be in the Conservative election manifesto, would extend to any activities that “justify hatred” against people on the grounds of religion, sexual orientation, gender or disability.