Dozens of former WH Smith stores are likely to close, putting thousands of jobs at risk under a radical restructuring plan by their new owner, which had rebranded the shops to TG Jones,

The investment company Modella Capital, which bought WH Smith’s chain of 480 high street stores for £76m last year, blamed “weak consumer spending” as it set out the plan to landlords on Wednesday.

Eight of the chain’s remaining 450 stores will close immediately, while Modella is demanding 100% rent holidays on about 100 more, as first reported by The Telegraph.

The company also wants 5% rent reductions on hundreds more stores for a year, with cuts of between 15% and 75% beyond that period, according to a document seen by the Guardian. If landlords refuse the rent holidays and cuts, the stores could shut.

When Modella acquired the chain – which employs 5,000 staff – the shops were renamed under the fictitious “family” brand name of TG Jones, ending 233 years of the WH Smith name on the British high street.

On Wednesday, Modella said rising costs and geopolitical events had also contributed to TG Jones remaining lossmaking, while admitting that the name change had also hit trade.

The restructuring plan must be approved by a vote from creditors and through a court process.

A TG Jones spokesperson said: “This decision has not been taken lightly. While we continue to believe in the strength of the core business, TG Jones has experienced highly challenging trading conditions over the past year, along with many other brick-and-mortar retailers.

“Weak consumer spending and cost of living pressures, combined with rising operating costs as a direct result of government policy and recent geopolitical events, have meant that the company as a whole has remained lossmaking.

“The forced name change from WH Smith has also negatively impacted consumer awareness, despite the fact that the proposition has improved.”

It said the plan was an “essential part of the company’s turnaround” under which Modella would invest £35m. It said the restructure was “designed to protect the substantial core of the store estate and create a stronger, more sustainable business that can continue to serve customers for years to come”.

However, industry insiders said that Modella had always intended to close dozens of TG Jones stores to create a slimmed-down chain of 350 shops once a block on doing so under its deal with the WH Smith parent company ends in June.

“This has been the intention all along,” the source said. “Nobody wants almost 500 sites [in the UK].” The source added that turning the business around in the current retail climate would be tough, with perhaps a “one in three chance” of creating a proposition to draw in enough shoppers.

TG Jones is likely to struggle to win support from landlords as its difficulties come after the collapse of fellow Modella-owned chains Claire’s and The Original Factory Shop, which have now closed all stores with the loss of about 2,500 jobs. Modella’s Hobbycraft chain also closed numerous stores under a restructure last year.

WH Smith’s travel stores, which were not part of last year’s deal and remain owned by the stock market-listed group, continue to trade unaffected.

First established in 1792 in Little Grosvenor Street in London by Henry Walton Smith and his wife, Anna, WH Smith expanded to become one of the UK’s best-known retail chains. It grew rapidly in the 19th century, building a newspaper distribution business with the expansion of the railway network. It opened its first retail travel store in Euston station in London in 1848.