UK retailers have launched a barrage of discounts to try to clear stock after a month of falling sales as soaring inflation and bills hit households’ budgets and a warm autumn reduced demand for coats and boots.

On Monday, New Look was offering a 50% discount off all products, Asos up to 80% off almost all lines and Boohoo 30% off everything, with many other fashion retailers – including Marks & Spencer, River Island and Matalan – offering between 20% and 30% cuts.

The discounts came as industry insiders warned a number of online fashion sellers had experienced year-on-year sales falls in November of more than 10%.

Online retailers have been hit particularly hard by a combination of the unseasonably mild weather, which affects sales of higher-priced coats, sturdy footwear and knitwear, the cost of living pinch on shoppers’ spending power, and more competition from a high street bouncing back from 2021’s Covid lockdowns and Omicron fears.

Despite that recovery, physical stores are still suffering. UK shopping destinations recorded a 4.2% year-on-year uplift in the number of visitors in the week to Saturday 26 November, which included the Black Friday discount day. However, visitor numbers remained 14% down on pre-pandemic levels with coastal and market towns and regional cities particularly struggling to bounce back.

The Confederation of British Industry (CBI) said retailers were “feeling the chill” with sales going into reverse this month and a similar level of decline expected in December after an increase in October.

Its headline retail sales balance – which marks the difference between the percentage of retailers reporting an increase in sales and those reporting a decrease – fell to -19% in November from +18% last month, and is forecast to slide to -21% in December.

Martin Sartorius, the CBI’s principal economist, said the survey results “underline what a tough time it is for the sector”.

He said: “It’s not surprising that retailers are feeling the chill as the UK continues to be buffeted by economic headwinds. Sales volumes fell at a firm pace in the year to November, and retailers remain notably downbeat about their future business prospects. This pessimism is reflected in investment intentions worsening to the greatest extent since May 2020.”

Kien Tan, a retail expert at advisory firm PricewaterhouseCoopers, said online retailers appeared to be discounting more as they found life harder. “The overall pie has shrunk for online retailers,” Tan said, suggesting discounting was likely to get more intense closer to Christmas as retailers try to clear stock before the economic crunch expected next year.

However, he said the overall level of discounting appeared to be similar to last year with fewer retailers offering blanket discounts and most focused on trying to shift cold weather gear.

Those with warehouses groaning with piles of unsold fashion built up for the winter are keen to clear unwanted stock as the cost of storage has almost doubled since the pandemic began.

The shipping firm Maersk said low demand and full warehouses mean its clients are reluctant to pick up their imports from ports and it has reportedly offered to slow down cargo ships to ease pressure in the UK.