Tesco, which revealed the closures in January, has already confirmed that 2,000 jobs are under threat but the Sunday Telegraph reported that the figure could be five times higher as boss Dave Lewis attempts to reverse sliding profits.
Around 6,000 of the job losses would be from head office and the 43 store closures, with the rest coming from an overhaul of the supermarket's operating practices, according to the report.
Tesco, which has a British workforce of more than 310,000, had unveiled plans to shut unprofitable branches, sell assets and axe its shareholder dividend in a bid to revive its fortunes after an accounting scandal.
Lewis hopes to cut head office costs by 30 per cent, saving 250 million pounds (USD 385 million, 338 million euros).
Tesco, suffering from fierce competition in Britain from supermarket price wars and German-owned discounters Aldi and Lidl, also faces various probes after the giant admitted in October to having overstated its profits by 263 million pounds.