The Japanese firm told workers it proposed to close the vehicle manufacturing plant at the end of the current model’s production lifecycle.
The plant currently produces 150,000 cars a year.
A statement said: “This proposal comes as Honda accelerates its commitment to electrified cars, in response to the unprecedented changes in the global automotive industry.
“The significant challenges of electrification will see Honda revise its global manufacturing operations, and focus activity in regions where it expects to have high production volumes.”
Honda said under the proposed restructure, the current role of its UK manufacturing business (HUM) as a global manufacturing hub may no longer be viable.
There was no mention of Brexit in Honda’s statement.
Consultation with the Unite union will begin today, and Honda said it will be working closely with its workforce over the months ahead.
Katsushi Inoue, Honda’s chief officer for European regional operations and president, Honda Motor Europe, said: “In light of the unprecedented changes that are affecting our industry, it is vital that we accelerate our electrification strategy and restructure our global operations accordingly.
“As a result, we have had to take this difficult decision to consult our workforce on how we might prepare our manufacturing network for the future. This has not been taken lightly and we deeply regret how unsettling today’s announcement will be for our people.”
HUM director Jason Smith said: “We understand the impact this proposal will have on our associates, wider supplier base and the local community. We are committed to supporting associates to help them through this difficult time.”
Business Secretary Greg Clark said: “Honda have announced, as part of a global restructuring, plans to close their Swindon plant in 2021; and instead manufacture and export the new Civic model into Europe from Japan. As Honda have said, this is a commercial decision based on unprecedented changes in the global market. Regardless, this is a devastating decision for Swindon and the UK.
“This news is a particularly bitter blow to the thousands of skilled and dedicated staff who work at the factory, their families and all of those employed in the supply chain.
“I will convene a taskforce in Swindon with local MPs, civic and business leaders as well as trade union representatives to ensure that the skills and expertise of the workforce is retained, and these highly valued employees move into new skilled employment.
“The automotive industry is undergoing a rapid transition to new technology. The UK is one of the leaders in the development of these technologies and so it is deeply disappointing that this decision has been taken now.”