Penny Mordaunt took a deep breath, her toes gripping the 7.5-metre diving board, before hurling herself backwards into the void. A second later she crashed belly-first into the water. Television viewers across Britain gasped and then winced.

Eight years after introducing herself to the nation in the shortlived celebrity diving show Splash!, Mordaunt this week took on an even more audacious challenge: launching a bid to become Britain’s next prime minister.

This time, the execution has been perfect. Mordaunt entered the race in an upmarket Indian restaurant, the crowd sweating through London’s heatwave. But she kept her cool, overtly tapping into the Conservative party’s enduring Thatcher worship and promising to return to the “old stuff”: low taxes, a small state, personal responsibility.