Sajid Javid continues to bulldoze Theresa May's political legacy at the Home Office. The Home Secretary has announced that from autumn, medicinal cannabis will be available for prescription on the NHS.

The move follows a burst of negative publicity for the government on the issue last month, when two cases involving young boys whose epilepsy is medicated with cannabis oil – Billy Caldwell, 12, and Alfie Dingley, six – sent the question of legalising and regulating the drug to the top of the news agenda.

Where Javid and Jeremy Hunt, then health secretary, demonstrated an openness to changing the law on medicinal use of the drug, all May could do at the time was issue a limp defence of a status quo (she insisted there was “very good reason” for keeping the strict rules that led to Billy Caldwell being hospitalised). It was a characteristically flat-footed response – most likely borne of her personal hostility to drug liberalisation – and one that only exacerbated a slew of negative publicity.

That the Home Secretary has effectively overruled her is therefore very telling. He has taken a sledgehammer to another of the pillars of the May Home Office – a draconian approach to drug legislation. Having already done away with the hostile environment approach to immigration, and trashed caps on visas for skilled workers, his iconoclastic streak shows no sign of abating. May has increasingly little left to show for her six years as home secretary.

That Javid has been able to comport himself in his new ministerial gig with such zeal highlights the fundamental weaknesses of May as Prime Minister: she is unable to respond intuitively and swiftly to emotive, easily-resolvable policy issues that animate the public, cannot take decisions, and cannot impose her authority on ambitious ministers who seek to fill the vacuum where she ought to be, as Javid has. Those shortcomings will be felt on a far wider range of issues in coming weeks and months.