It is the seemingly benign garden game which – as all children secretly understand – actually offers unrivalled opportunities to legitimately smash a tennis ball straight at underprepared sibling.

Now, while there is certainly no suggestion it was deliberate, a colleague has taken the chance to do just that while playing Swingball with Nicola Sturgeon.

The Scottish first minister agreed to have a knock around with former SNP MP Anne McLaughlin while out canvassing in Glasgow.

But the party leader – well known for dishing out blows to opponents in both Holyrood and Westminster – was perhaps not expecting the ferocious head-height serve offered up by her fellow member.

Video shows the ball crashing straight into Ms Sturgeon’s head, before she apparently throws in the towel.

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“Outrageous,” someone in the crowd can be heard saying in footage of the incident. “Outrageous.”

But Ms Sturgeon proved she could roll with the blow following the incident on Saturday afternoon.

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“Great time in Dennistoun today – until the moment @AnneMcLaughlin whacked me on the head with a tennis ball,” she later tweeted.