Middle-class US consumers are increasingly leaving their credit cards at home when they go shopping, extending a trend first shown by Wal-Mart’s low-income shoppers last year, and adding to the pressures on US retailers’ sluggish sales.

Mainstream retailers are reporting that shoppers are opting for debit cards or cash instead of credit cards as they face tighter credit limits, illustrating how the wider credit crunch is being transferred to main street spending.