LONDON (AP) — Britain's government is expected Tuesday to back a plan to expand London's Heathrow airport despite concerns about air pollution, noise and the destruction of homes in the capital's densely populated western neighborhoods. Transport Secretary Chris Grayling will inform Parliament of the government's decision on how to expand London's airport capacity. The issue was so toxic that politicians created an independent commission to weigh the options — and it decided to expand Heathrow. [...] it is up to political leaders to make the final decision, and authorities have stalled.