Sherif’s apparent opportunism came as no surprise to Tennant. The man usually wasted no time at throwing petrol on the fire. A self-proclaimed cleric with a dubious history in Syria and a conviction for fraud, he now seemed to spend his life, in Tennant’s view, touring TV studios denouncing the police.

There was a trace of irritation in the PM’s expression. ‘We’re pushed for time, Ben, so I’d rather keep focusing on the facts right now, if that’s okay. COBRA in fifteen minutes. Ben, can I grab five minutes?’

The meeting dispersed. As the door closed behind him, Tennant could hear raised voices. The head of MI5 raised an eyebrow in Tennant’s direction.

‘Was that my imagination or was our beloved Home Secretary a little testy just then?’ she said quietly.

‘Probably just stress,’ said Tennant tactfully. But privately he agreed. The fault lines between these two most senior figures in the government had come to the surface since the election. Thomas had been the architect of the coalition deal and it was public knowledge that the Home Secretary had fought hard to persuade the PM to get into bed with Lesley Hogarth.

And that wasn’t the only thing that had changed. Thomas had increasingly become sceptical about the threat of the extreme far right, presumably, Tennant thought, as a gesture to his coalition partners. But that was the first time he’d challenged Tennant directly. Worth watching the old fox, he thought as he followed the civil servants towards the Cabinet Office.

#

Behind Downing Street’s public facade of charcoal bricks and chalk-white windows lies a labyrinth of rambling passages, cramped offices and handsome state rooms that stretch from Number Twelve at the Horse Guards Road end to the Cabinet Office on Whitehall. It was through this maze that Tennant scurried, a few steps behind the civil servants as they twisted their way past sombre Georgian anterooms, along 1960s corridors floored with nylon carpets, and up and down tatty stairs originally built for the servants of eighteenth-century aristocrats. The route, Tennant mused, resembled so much of the UK’s political system – cobbled together from old and new, ramshackle in places, utterly long-winded, and yet usually managing to get there in the end.

COBRA crisis meetings were a frustrating mixed blessing for Tennant. The principle of getting security services and decision-making ministers around the table during a crisis was sound, but they were also called by prime ministers for public show – to tell the public that their political masters were in control, even if facts suggested otherwise. Twenty years ago, the public was unaware of COBRA, now they were a hybrid of a national crisis management meeting and PR event.

The meetings took place in a suite of windowless offices below street level in the Cabinet Office, far from prying electronic ears. Civil servants love a good acronym and so early in the 1970s, soon after the first gathering took place to discuss the miners’ strike, the location of the suite – Cabinet Office Briefing Room A – became COBRA. The first time Tennant attended, he was struck by how much the venue resembled a Hollywood director’s vision of what a top-secret room should look like with its beech-panelled walls, black leather chairs and a wall of TV screens.