the Imp came about because of the fuel shortage caused by the Suez Crisis in 1956. Petrol was rationed in the UK, sales of the heavy cars for which Rootes was known had dramatically slumped, and there was a huge market for small economical cars with good fuel economy. The BMC's Mini had already taken advantage of the opportunity, with production starting in 1959. The market for small cars was soon recognised and it was evident that Rootes needed to develop their first small, economical car.

They came up with a bold and innovative design with a rear mounted water-cooled four-cylinder power unit based on the Coventry Climax FWMA fire pump engine, all-aluminium alloy with an overhead camshaft, combined with a full-syncromesh aluminium transaxle. This was very advanced at the time. The car had a lift-up opening rear window and folding rear seats, again a unique feature on a small car.

The Imp was a massive and expensive leap of faith for Rootes who did not have recent experience of building small cars. They built a new, computerised assembly plant on the outskirts of Paisley, in Linwood, in which to assemble the Imp. The UK Government Regional Assistance policy provided financial grants to the Rootes Group to bring approximately 6,000 jobs to the area. Linwood had become an area of significant unemployment because of redundancies in the declining shipbuilding industry on the nearby River Clyde. The workforce, recruited mainly from the shipbuilding industry, did not bring the distinct skills necessary for motor vehicle assembly, and Imp build quality and reliability suffered accordingly. Industrial relations were also an issue in production. Disputes and strike action became a regular occurrence, as was the case in many parts of British industry in the 1960s and 1970s.

Although ahead of its time, the Imp suffered from build and reliability problems, which harmed its reputation and led to the Rootes Group being taken over by Chrysler Europe in 1967. The Imp continued in production until 1976, selling just under half a million units in 13 years.