England’s Ashes preparations have been rocked after spinner Jack Leach was ruled out of the series with a back stress fracture.

Leach claimed four scalps during England’s 10-wicket victory over Ireland at Lord’s this week, but developed low back symptoms during the match.

A subsequent scan on Sunday revealed a stress fracture in the lumbar region of the spine, which will rule him out of all five Ashes Tests.

“Spinner Jack Leach has been ruled out of the LV= Insurance men’s Ashes series with a low back (lumbar) stress fracture,” an England statement said.

“England will announce a replacement for the Ashes series in due course.”

The news is a huge blow for England head coach Brendon McCullum and captain Ben Stokes, who have repeatedly talked up Leach’s importance during their 12 months in charge.

The 31-year-old impressed during the winter tours of Pakistan and New Zealand to improve his Test tally to 124 wickets in 35 matches.

A strong start to the domestic season with Somerset, where he claimed 18 scalps in six LV= Insurance County Championship fixtures, further increased the belief Leach could play a key role in the Ashes despite struggling during the previous series in Australia.

Leach started the Test summer by tormenting Ireland at Lord’s on Thursday with three for 35, going at an economy rate of 2.50, and picked up a wicket with his second ball on Saturday.

However, Leach left the field after only three overs and when he returned came under attack from Andy McBrine in particular to eventually concede 90 runs from 20 overs.

Leach’s absence from the Ashes, which begin on June 16 and conclude at the end of July, will significantly change the make up of Stokes’ bowling line-up.

The Somerset bowler was the only spinner named in the 16-man squad on Saturday for the first two Tests and England’s depth in that area will now be tested.

Leg-spinning all-rounder Rehan Ahmed is highly regarded after becoming the youngest man to play Test cricket for England during the Pakistan series, while orthodox spinner Will Jacks picked up six wickets in two Tests in December.

Matt Parkinson played against New Zealand last year but has fallen out of favour and left-field options for England include tempting Moeen Ali or Adil Rashid out of their red-ball retirement.

England do have an array of seam options, but James Anderson and Ollie Robinson were rested for the Ireland Test with minor niggles and Jofra Archer has already been ruled out of the summer action.

Olly Stone is also currently sidelined with a hamstring issue and concerns remain over captain Stokes’ ability to bowl due to a long-standing left knee injury, which only heightened Leach’s growing role in the side.