Bonmarché has suffered a decline in full-year sales as online growth failed to offset “disappointing” performance across its store portfolio.

The fashion retailer said like-for-likes slipped 1.5% during the 52 weeks to March 31, driven down by a 4.5% slowdown in comparable store sales.

In contrast, online sales surged 34.5% across the year.

Bonmarché found trading particularly tough during its fourth quarter, when store like-for-likes slumped 11.1% and group like-for-likes, including online sales, fell 7.4%.

Despite the like-for-like declines, Bonmarché said total sales dipped just 0.5% across the year and that gross margins remained “resilient”, as tight stock control and improvements to its loyalty scheme led to lower discounting.

It insisted that pre-tax profit would be “in line with the board’s expectations” when it reports full-year results on June 19.

Bonmarché said it made “good progress” during the financial year, although it admitted that store sales performance was “disappointing”.

It blamed “issues more widely reported in the clothing market” for the bricks-and-mortar sales slowdown.

A number of its fashion rivals including New Look and Marks & Spencer are grappling to rebuild high street performance.

Bonmarché added that it made “significant” cost savings throughout the year, driven by “improved operational efficiency” and reduced marketing spend.

The retailer’s chief executive Helen Connolly said: “As anticipated, trading conditions in the final quarter of our financial year remained challenging and, against this backdrop, I am pleased that we have delivered an increase in the FY18 profit before tax compared to last year.

“While we expect the market to remain difficult, our focus will be on continuing to improve our proposition to customers through a number of self-help initiatives, which we expect to drive further progress for the business during the new financial year.”