1989. When two old friends, the 'much feared inquisitor', Brian Walden, and 'Iron Lady' Prime Minister, Margaret Thatcher, come together for their last ever TV interview, little do they realise they're about to embark on one of the most infamous political exchanges of all time. The 45-minute showdown became a national talking point and set in train a series of events that ended with Margaret's resignation.Afterwards, they never spoke again…