The Conservative party’s efforts to draw a line under the "Tatler Tory" scandal have suffered a blow after a film emerged showing Theresa May praising the activist at its centre.

The film from two years ago shows the future Prime Minister giving a speech in which she says Mark Clarke’s campaign group has done “absolutely tremendous” work.

Clarke was later thrust into the limelight when 21-year-old activist Elliott Johnson killed himself in 2015 having complained of being bullied by him.

In the film passed to the Mail on Sunday, Ms May can be seen at a rally of enthusiastic campaigners, with Clarke standing by her.

She says: “What you are doing is absolutely tremendous. Road Trip 2015 is great. Thank you Mark for all you are doing.”

There is no suggestion that Ms May knew anything about the allegations that were eventually made about Clarke.

But the footage will once again draw attention to the prominent role he held in the Tory election campaign.

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It comes after a Tory-commissioned report into circumstances around Mr Johnson’s death found Clarke, once tipped for greatness by Tatler magazine, had become subject to a string of allegations of bullying and sexually inappropriate behaviour, all of which he denies.

The report went on to effectively clear senior Tories like then chairmen Grant Shapps and Lord Feldman of having known anything about the allegations before August 2015.

Mr Johnson’s father branded the report a “whitewash” when it was published this week.