John Lewis, which is planning to open a new store in Birmingham, reported a 10.8 per cent fall in sales for its Solihull store last week, raising fears over faltering consumer spending.
Overall, the chain saw a 3.8 per cent drop nationwide.
The retailer revealed earlier this year that it will open a £100 million store in Birmingham’s New Street station redevelopment, and is expected to open another store in Tamworth.
The employee-owned firm said it had a "challenging" seven days in the week ended March 26.
John Lewis buying director, home, Paula Nickolds said: "The seasonal calendar had a big impact last week, and with Easter and Mother’s Day falling three weeks later this year, sales comparisons are challenging.
"Customers also seemed to be enjoying the arrival of spring and, given an average temperature rise of 3 degrees, it’s no surprise that sales of outdoor furniture, gardening and sunglasses saw strong weekly uplifts.
"However, this warm weather did have an impact on footfall in shops across fashion and home, resulting in a tough week for overall trade."
Falling sales at John Lewis, along with high-profile collapses at firms like Oddbins and Officers Club in the last few days, are contributing towards a pessimistic outlook in the retail sector.
Global Insight economist Howard Archer said: "The latest John Lewis sales fuel concerns over the deteriorating health of the UK consumer.
"There has been a worrying stream of retailers recently reporting more difficult trading conditions in the first quarter of 2011 and this is being borne out in the weekly sales figures from John Lewis.
"This is particularly significant as John Lewis has been very much an out-performer in the retail sector."