JD Sports Fashion plc (LSE:JD.) has emerged as a serious contender to rescue Debenhams plc, in a potential takeover that would significantly escalate its high street rivalry with Mike Ashley. The company is understood to be examining Debenhams' finances in a secure data room, having been granted increased access in the last fortnight. A surprise rescue by JD Sports would intensify the long-running retail duel between its chairman Peter Cowgill and Mike Ashley, who controls Sports Direct and the department store House of Fraser.

One source close to its finances said the chain retains some valuable assets including its online business, its cosmetics department and some of its concessions. Dozens of its 124 stores could be saved, the source said. Alternatively, Debenhams could still be broken up for parts.

However, there remain fears that the chain will be liquidated if a rescuer ­cannot match the potential returns for creditors. The specialist firm Hilco has been lined up to sell off stock and wind down Debenhams if no deal can be agreed at the end of what one party described as a “chaotic” process. Sir Philip Green, whose Arcadia group is one of Debenhams' biggest concession holders has approached lenders to secure around £30m in new funding to keep his retail empire afloat, Sky News reported.

A deadline to sell Debenhams is believed to have been extended following Boris Johnson's imposition of a second lockdown in England this month. Advisers are now racing to find a solution before non-essential stores are due to reopen in December for a truncated and crucial Christmas trading period. The JD Sports chairman said officials had “been taken in by the self-serving testimony of one notoriously vocal competitor”.

Debenhams and JD Sports declined to comment.