Top Gear presenter Clarkson’s comments, made on The One Show yesterday, provoked outrage. When asked what he thought should happen to those taking part in the strikes, he joked that they should be executed in front of their families.

Now Unison said it is taking “urgent legal action” over the “appalling” comments and is threatening that it may sue.

Meanwhile, David Cameron has weighed in to the fiasco, saying that his friend Clarkson was “silly” to joke about shooting the strikers.

Top ten Jeremy Clarkson gaffes

“It was obviously a silly thing to say and I am sure he didn’t mean that,” Cameron said on ITV’s This Morning programme.

“I didn’t see the remark but I’m sure… it’s a silly thing to say.”

In reference to the strikers, Clarkson told One Show presenters yesterday that: “I’d have them all shot. I would take them outside and execute them in front of their families.”