Can anyone remember the title and actors of this film? Thanks!

I watched an old English movie about the director of a poll company who helped a guy elected as the PM and manipulate him eventually replaced him. He also managed to make people to surrender almost dictatorship power to him at the end. Some episodes include that they sent a special force th rob the gold of the Swiss bank then claimed they found gold in north sea, the new PM use TV to do direct democracy by asking people to vote through it to decided every trivia issues... Can anyone remember the title and actors of this film? Thanks!