Harriet Jones, MP for Flydale North, was catapulted from the quiet, dutiful world of a lifelong backbench politician when she stumbled across a plot where the alien family, the Slitheen, had infiltrated the government and planned to trigger an interplanetary war.
Trapped inside Number 10 with the Ninth Doctor and Rose Tyler, and the family Slitheen about to start a nuclear conflict, Harriet was the only elected representative in the room to take decisive action, authorising a sub-Harpoon missile to be fired at them in Downing Street.
Later, after serving as Prime Minister for three successive terms, her path crossed with the Doctor’s once again, this time as his Tenth incarnation battled the Sycorax.
Controversially, Harriet Jones ordered the secret organisation, Torchwood, to fire and destroy the fleeing Sycorax ship as a warning to other alien races who might try and invade Earth. A furious Doctor started rumours which set in motion her political downfall.
A few years later, Harriet bravely sacrificed herself to the Daleks in defence of the Earth and to help the Doctor.