Will and Jaden Smith: Like father, like son when it comes to pushing your movies

From left to right, Bradley Cooper, Heather Graham, Jaden Smith,Will Smith, Alfonso Ribeiro and DJ Jazzy Jeff on the decks behind during filming of the Graham Norton show at the London Studios (PA)

Long established as one of the most potent forces in Hollywood, Will Smith now insists on coming with an added twist: namely his teenage son and current co-star, Jaden.

Promoting their new film, After Earth, the Will and Jaden roadshow has hit London in recent days, hammering home the new family double act with inevitable vigour. Jaden, 14, already boasts a career of his own, most notably taking the lead role in the 2010 remake of The Karate Kid. But Will and Jaden? This is a potentially tougher sell and Smith senior is pulling out all the stops to seal the deal – and he of course has plenty of stops to pull.

The pair were seen showboating with fellow shy-and-retiring type Boris Johnson in the Mayor’s office, and delivering a lively turn on Graham Norton’s chat show. Many of Norton’s fans will have briefly died a little inside when the savvy Irishman was obliged to suggest the Smith boys perform a “spontaneous” rap. As they confidently grabbed the microphones and broke into the first of four numbers, spontaneity was the one thing that didn’t come to mind.

Now 44, the one-time Fresh Prince of Bel-Air seeks to combine his trademark funny and irreverent public demeanour of old with a new faux disapproval of his cocksure Mini-Me, ready to slap him down gently when he feels junior’s rawer anecdotal skills need steering in the right direction.

Like I say, a tougher sell. I also wouldn’t bet against them.