Debenhams has admitted it will not meet the profit forecast it made less than two months ago after a drop in sales.
On 10 January, the department store chain said it was on track to hit its profit target, but now says it is "no longer valid".
It comes as like-for-like sales for the six months to the start of March were down 5.3% compared with the same period last year.
Sergio Bucher, chief executive of Debenhams, said: "We are making good progress with our stakeholder discussions to put the business on a firm footing for the future.
"We still expect that this process will lead to around 50 stores closing in the medium term."
Mr Bucher added that the retailer would need support from landlords and local councils to tackle rising rent and business rates.
Last year, Debenhams reported a pre-tax loss of £491.5 million, the highest in its history and soon after warned that sales fell sharply over the Christmas period. With 165 stores across the UK, Debenhams has come under increasing pressure from the decline of the High Street and rising online sales.