Cheshire based cleaners Johnson Service Group are closing 100 stores as part of a restructuring that will cost the company almost £24 million.
Johnson has already closed more than 50 outlets in recent years as it battled tough conditions on the high street.
The group said a typical store has one full-time and two part-time employees, while there will also be cut-backs in back office and warehousing staff, suggesting that at least 300 jobs will go in total by the end of 2012.
None of the locations earmarked for closure have been revealed but they are understood to be mainly outside London and south-east England.
The UK's largest dry cleaning chain, Cheshire-based Johnson Service Group, is to axe more than a fifth of its stores this year, a move that will trigger hundreds of job losses.
Johnson Service Group said it will close 100 of its 460 Johnson Cleaners stores.