The human resources team at Tesco must be racking up overtime.

The exit of Tesco Ireland chief executive Phil J Clarke, who has announced his retirement is but the latest senior management change at the embattled retailer since "Drastic" Dave Lewis took over the group in September.

Clarke has bowed out less than two years into his tenure. He joins a slew of senior executives who have left Tesco in recent months, most of whom were suspended following an accounting scandal at group headquarters last year.

The outgoing Irish chief was not implicated in any way with the accounting scandal, but he would have been viewed as a part of the regime of his namesake, Lewis’s predecessor, Phil Clarke, who appointed him. Sources said Clarke’s retirement is entirely voluntary and was not enforced by Lewis, who recently lived up to his “drastic” nickname by shuttering Tesco’s main UK headquarters.

Clarke's retirement nevertheless provides Lewis with the opportunity to shake up the Irish unit and staunch the alarming flow of its customers to the discounters, Aldi and Lidl. Tesco Ireland, with 25 per cent market share, is also on the verge of being toppled as Ireland's largest grocer by Musgrave's Supervalu.

Clive Black, head of research with Shore Capital, said Clarke's departure was "not wholly surprising".

“Clearly, Dave Lewis sees the need for change. Much is being done and needs to be done for Tesco to stabilise and grow again. Effective management is central to this process and Lewis isn’t hanging about,” he said.

Black expects to see “a flattening in Tesco Ireland’s market share and a gradual improvement in sales as improved store standards, sharper prices and the outcomes of category reviews are implemented in forthcoming quarters”.

Andrew Yaxley, Clarke's incoming replacement, will have quite the in-tray when he takes the reins next month.