How badly do you have to mess up, these days, before you’re not allowed in Theresa May’s cabinet? Just how far does tolerance stretch? You might imagine Chris Grayling to be the ultimate prototype in this real-world experiment, with his granting then cancelling of a £13.8m ferry contract to a ferry company with no ferries, but let us also observe the progress of Liam Fox.

Fox is one of the most vocal and optimistic Brexiteers in politics. In 2016, he declared that a trade deal with the EU would be “one of the easiest in human history”. In 2017, he promised to “replicate the 40 EU free trade agreements that exist before we leave the European Union so we’ve got no disruption of trade”, and they would be ready “one second after midnight in March 2019”.

Yesterday, six short weeks before that midnight, it was revealed that Fox, as secretary of state for international trade, has managed to “roll over” just six of the 40 trade deals. This is not surprising. Britain is a considerably smaller trading power than the EU, and is moreover up against a deadline – most countries are likely to want to adjust trading terms in their favour.

What is surprising is that Fox promised he could pull off this feat in the first place, and then, having failed, responded to questioning with further flights of optimism. Having been hauled in to the House of Commons to defend his lack of progress, he responded by insisting it was always going to go “down to the wire” (23 of the aimed-for deals have now been marked as “significantly off-track” or “not possible to be completed by March 2019”), and that it was “not a numbers game” – the focus should be on the “proportion of trade we can maintain” (one of the partners with which he has made a deal is the Faroe Islands. Those he has not include Mexico and Japan).

Fox, you’ll remember, was in 2011 forced to resign in disgrace from cabinet for allowing his close friend, sans security clearance, to take up an unofficial role at the Ministry of Defence. Adam Werritty was allowed access to Fox’s diary and into private MoD meetings. He also printed business cards describing himself as an adviser to Fox, which the subsequent official report said “risked creating the impression that Mr Werritty spoke on behalf of the UK government”. The report concluded Fox’s actions had put himself and others in the department at risk.

Yet how soon he has been rehabilitated – he was back in the cabinet just five years later. Little wonder if he feels invincible. Fox is not only being allowed multiple chances to fail, but multiple chances to clearly signpost exactly how he will next fail, before being given the powers to go ahead and do it. All he needs is the confidence to brazen it out – to simply refuse to admit a failure is a failure.

This seems to work even as politicians such as Fox and Grayling are criticised at ever greater volume by the media. Bad headlines used to end careers – now they are something to brush off. Ministers can simply refuse to be humiliated – rolling their eyes at reporters who question them, before getting on with the next bad decision. So desperate is Theresa May for allies that she will reward loyalty over competence – and even over honesty. As the media loses its bite, this is something to fear.

• Martha Gill is a political journalist and former lobby correspondent