UK Celebrity Traitors comes to a climax in nail-biting finalThe second series of the hit show reached its climax on Friday after attracting 15 million viewers.4 hrs agoCulture

• Spoiler warning: This story reveals details of The Celebrity Traitors final

We’ve had four weeks of suspense, suspicion and very suspect tactics, as some of Britain’s biggest stars engaged in a battle of wits to win the most popular show on TV.

The second series of BBC One’s The Celebrity Traitors reached its climax on Friday, with the 21 original contestants having been reduced to seven before the final.

They were then whittled down to two winners – with the faithful duo of comedian Romesh Ranganathan and Heartstopper actor Sebastian “Bash” Croft emerging victorious.

• As it happened: Relive the Celebrity Traitors final
• Watch The Celebrity Traitors on BBC iPlayer
• Get all the reaction on Uncloaked on BBC iPlayer

More than 15 million people have been tuning in to this series, with the finale drawing in a record average audience of 11.2 million live viewers. This number will also rise when people who turn to catch-up to watch the episode are added.

Kenny reached the final stage, the endgame, after turning on his fellow traitor Maya at the last round table.

Kenny, Romesh and Bash were joined by singer James Blunt in the climax of the endgame, where the remaining contestants gather around a fire pit to decide whether they think there are any traitors left.

When James and Kenny were tied in a vote for who was a traitor, Bash persuaded Romesh to banish Kenny instead of James – thereby securing victory for team faithful.

“Absolutely devastated. Almost scraped it,” Kenny seethed. “I was so close, I smelled the victory.”

However, he can take consolation from the fact his performance on the show has established him as a mainstream star.

In a further twist, James chose another round of voting and was subsequently evicted himself, leaving Romesh and Bash as the last men standing.

“This might actually be the best day of my life,” said 24-year-old Bash through tears of joy.

He, too, can expect a major career boost.

Romesh reflected: “I just really hope my mum’s proud. And also my youngest son Charlie, who wanted me to come on the show – dad won. Please show me some respect.”

The pair will split their winnings between two refugee charities, the Refugee Council and Choose Love.

Earlier, actor Michael Sheen was murdered in the first action of Friday’s episode. “I am incredibly disappointed,” he said. “Gutted that I got so close to the end. It’s been absolutely unforgettable.”

When it came to the endgame, Little Mix singer Leigh-Anne Pinnock was swiftly banished after Kenny voted to remove her.

“I was thinking me and him had a mutual understanding, and now I feel so stupid,” she raged.

“But I’m walking away feeling super proud and like I’ve really accomplished something here.”

Meanwhile, James B was left rueing one final mistake in a long but valiant catalogue of misjudgements throughout the series.

The singer, who looked aghast when he was attacked by Romesh during the endgame, was then the only one to choose to banish again when it came to the final three.

James was unaware that Romesh and Bash had both chosen to end the game – meaning he too could have been a winner if he had done the same – but became the victim of his own choice to banish.

“I’ve loved trying to work it out, I’ve loved getting it wrong so often, I’ve loved the tiny moments when I’ve got it right,” he said wistfully. “I’ve loved the game.”

Celebrities who departed earlier in the series included ex-EastEnders actor Ross Kemp, model Jerry Hall, sitcom star Miranda Hart, comedian Joe Lycett, presenter Hannah Fry and former BBC journalist Amol Rajan.

This series is also likely to be remembered for the two contestants who made the unorthodox decision to reveal themselves as traitors, before being summarily dispatched by their fellow players.

First, actor Richard E Grant was so giddy to have received the tap on the shoulder that he blurted out his supposedly secret status in episode two.

Comedian James Acaster, meanwhile, was the most reluctant traitor in the history of The Traitors, and unexpectedly gave himself up when he came under pressure at the round table in Thursday’s penultimate episode.

There have been reports that filming of the scene was paused and he was checked by welfare staff after he became anxious.

Asked about the reports, a BBC spokesperson said on Friday that the safety and welfare of those taking part was the “highest priority”, and “players are closely monitored and supported throughout by production which includes a dedicated and experienced welfare team”.

Speculation about the round table being heavily edited was fuelled when eagle-eyed viewers noticed a shot of Romesh reacting in shock – apparently to James A’s initial confession – which in fact seemed to have come from a later moment, after Romesh had voted for James by writing his name on the blackboard.

In the episode, the sequence where the celebrities all voted for James in light of his admission was shown as a relatively quick and straightforward process, raising a question about what prompted Romesh’s shocked look.

Acaster did not take part in Friday’s edition of spin-off show Uncloaked, which reunited some of the celebrity contestants following the final.

The comedian’s bombshell the previous night did provide the programme with a twist to spark it to life after what some viewers saw as a mid-series lull.

On Thursday, the Hollywood Reporter noted that the show had achieved record-breaking ratings – before asking: “Why, then, has much of the consensus on social media been that it’s all felt a bit dull?”

Some noted a shortage of true back-stabbing, double-crossing and explosive rows – the things, in other words, that viewers love the most – while the celebrities were more chummy and savvy than previous groups of castle dwellers.

And while there was no shortage of big characters, this season lacked an equivalent to Alan Carr, the hugely popular and apparently hapless comedian who lied and murdered his way to an unlikely victory as a traitor last year.

The drama ramped up in the final, though, and Friday’s episode is likely to have been the most watched TV programme of the year.