Mike Barry, director of sustainable business at Marks and Spencer, has announced he is to leave the UK retailer later this month.

Barry, who leads the group's eco and ethical programme Plan A, took to LinkedIn to announce his resignation, stating he will leave M&S at the end of June "after 19 fabulous years".

"Have loved every day working for a very special business and with an exceptional group of people stretching every sinew to deliver for customers, communities and planet alike," he wrote. "We have not got every part of the journey right but we've all achieved a lot together, learnt loads and shared with so many other good stakeholders the challenges and possibilities of sustainable change."

He added a "long-planned succession" will now see head of sustainable business Carmel McQuaid take the Plan A helm. 

In a statement, an M&S spokesperson said: "As we transform M&S, our commitment to doing business in the right way for our planet and communities remains at the heart of what we stand for. We'd like to thank Mike for his drive and leadership of our sustainability journey over the last decade and for the significant contribution he's made to the wider industry.

"We're delighted that Carmel McQuaid will now continue this work with a focus on how we integrate sustainability into each area of M&S as we build a family of accountable businesses."

Barry was promoted to director of sustainable business (Plan A) in October 2013 after serving as head of sustainable business at M&S for just shy of eight and a half years.

He recently represented M&S during the 'Sustainability of the Fashion Industry' inquiry, noting the importance of third-party auditors to ensure responsible practices at its UK factories.

Last year, M&S said more than three-quarters of its cotton is now procured from sustainable sources, putting the UK fashion, homeware and food retailer on track to meet its commitment to hit 100% this year.

In its 2018 Plan A report, published almost a year ago to the date, M&S said it uses around 50,000 tonnes of cotton annually, most of which is sourced through the Better Cotton Initiative (BCI).

M&S launched Plan A 2025 in June 2017 as it realised its 2020 commitments were reaching their conclusion. The retailer said at the time its activities needed "more ambition, a faster pace and greater scale."