Another week, another glossy espionage drama in which agitated politicos scour the corridors of power in search of something, anything, to differentiate the thing from its predecessors. But what? ITV’s Secret Service rummages through its faux-leather briefcase for fresh ideas. Not the easiest of tasks, given the number of cliches that swirl around the genre’s cufflinks. But God loves a trier. And Secret Service is nothing if not tenacious.

Might a protagonist who juggles family life with a secret job as an MI6 agent count as a USP, it wonders, nodding at Kate Henderson (Gemma Arterton) and her tousled action-bob. No? How about a plot that divides itself between Whitehall and a more exotic, if no less treacherous, location such as, say, Malta? Or many scenes in which actors in wool-blend car coats stride purposefully past the SIS building while shouting things like: “You’re the bloody home secretary!” and: “Tell that to the prime minister!”

“Um,” you reply, as politely as you can (it has a gun). “Er …”

Adapted by the ITV news anchor Tom Bradby and the writer Jemma Kennedy from Bradby’s 2019 novel, the five-part series follows the doughty Henderson as she power-walks through an aggressively generic thriller that takes in all of the above. Having infiltrated the fancy Malta base of a Russian oligarch, Igor Borodin (Miglen Mirtchev), Henderson and her crack team of undercover mavericks discover that a member of the cabinet may be a Russian asset.

Meanwhile, the resignation of the PM sees the launch of a fraught leadership contest. The most likely candidates are the faintly shifty home secretary, Imogen Conrad (Amaka Okafor), and the foreign secretary, Ryan Walker (Mark Stanley). An oleaginous sod in tasselled loafers, Walker’s off-piste activities – here a friendship with the Russian foreign minister, there a flirtation with nationalism – lead to much consternation among top brass. Is Walker the Russian asset? Or could the real mole be closer to home? Let us consider the possibilities slowly over five hours including ad breaks.

Secret Service is not, in any conceivable way, fun. It is not what you might call “a laugh”. There is no tension-puncturing “banter” or smartly veiled digs at the real-world government. At no point does a character tell a joke or fart himself awake in the manner of Slow Horses’ Jackson Lamb. Even the saucy stuff – a flirtatious Russian double agent; a sex tape involving a prominent politico – is handed to us solemnly, like a manila file across the desk of a senior civil servant.

This, rumbles ITV, is a serious drama with a serious message: a thriller with the brass neck and trousers to address hot-potato global skulduggery while focusing on its implications for Britain’s national security. “Democracy is stuffed,” it hisses from a darkened doorway, “so let’s crack open the all-butter biscuit assortment and watch Gemma Arterton pretend to drink white wine while she watches surveillance footage of the foreign secretary getting out of a Toyota Prius.”

As befits a thriller that concerns itself with the political here and now, Secret Service is stuffed with big, desk-thumping statements on the state of the nation. “The last thing we need is allegations of Russian collusion. We all know what happened in America,” shouts the PM (Steven Elder). “The well is poisoned,” drawls the MI6 boss, Sir Alan Brabazon.

Brabazon is played by Roger Allam, who once again bears out my theory that there is no programme on Earth that wouldn’t benefit from his presence. There are other fine performances, not least Rafe Spall as Henderson’s put-upon husband and Rochenda Sandall as a Downing Street aide whose growing awareness of her colleagues’ corruption forces her into an increasingly tight corner.

Secret Service doesn’t offer anything new. But it’s confidently paced and slickly directed (by the Oscar-winner James Marsh) and there are enough big things happening at regular intervals (murder, guns etc) to keep it all ticking over. And if you don’t like its stiff-jawed approach to cold war unpleasantness? Worry not. There’ll be another glossy espionage drama along next week.