The EM-2, also known as Rifle, No.9, Mk.1 or Janson rifle, was a British assault rifle. It was briefly adopted by British forces in 1951, but the decision was overturned very shortly thereafter by Winston Churchill's incoming government in an effort to secure NATO standardisation of small arms and ammunition. It was an innovative weapon with the compact bullpup layout, built-in carrying handle and an optical sight. The gun was designed to fire one of the first purpose-designed entirely new intermediate cartridges, designed to a 1945 requirement as a result of combat experience and German advances in weapons design during World War II. The round, the .280 British, was designed to replace the .303 round, which dated to the late 19th century. The EM-2 was intended to replace the Lee-Enfield bolt-action rifles and various submachineguns, while the TADEN would replace the Bren gun and Vickers machine gun. As part of NATO standardization efforts, the United States claimed the .280 British round was too weak for use in rifles and machine guns, and instead favoured the much more powerful 7.62×51mm NATO round. A bullpup layout for a British service rifle was finally adopted some years later in form of the SA80 assault rifle, which remains in service today. Development Post-war weapons The British Army entered World War II with infantry weapons based on the .303 British round, including the Lee-Enfield bolt-action rifle, Vickers machine gun and the Bren gun. The .303 had been developed near the end of the 19th century, and had several problems when used in modern designs, notably, the rimmed cartridge design that made it more difficult to use in a magazine. Although the Army had intended to replace the .303 on several occasions dating from before World War I, these efforts were repeatedly put off due to one crisis after another. There had been some consideration of a less powerful cartridge just prior to the start of WWII, using a 7.92 mm bullet, but in the aftermath of the Dunkirk evacuation, any interest in this development ended. In the immediate post-war period, Royal Small Arms Factory, Enfield began the development of a series of designs firing German rounds. Polish designer Roman Korsak was producing a new light machine gun firing the 7.92×57mm Mauser round using a mechanism similar to the FG 42 known as the EM-1, while Jeziorański was designing an infantry weapon firing the StG 44's