LONDON (Reuters) - UK member of parliament Nadine Dorries has delivered a scathing attack on her Conservative Party's leader Rishi Sunak in her formal resignation letter, accusing the prime minister of running a "zombie parliament" and lacking any political vision. Dorries, a close ally of former leader Boris Johnson, had announced in June she would quit and then faced mounting criticism for not actually doing so, preventing the election to replace her from being held alongside three other local votes last month. Dorries formally quit late on Saturday with a lengthy resignation letter that tor...