UK could lose coveted AAA rating, warns Fitch The Fitch decision came just a week before finance minister George Osborne presents his annual Budget to parliament. Only last month, Moody's also put Britain's top-notch rating on a negative outlook, implying a one-in-three chance of a downgrade. Fitch currently expects the UK's public debt to stabilize at around 94pc of its gross domestic product by 2014-15. Such a performance would allow it to reaffirm the country's ratings at AAA with a stable outlook, it said.