My focus now is on giving everything I've got to the white ball teams and helping England keep moving forward."I wish the Test team nothing but success Brendon has been understanding of that and accepting of that."Unfortunately, following on from the disappointment of the Ashes and then the subsequent loss against New Zealand, results mean we need to make a change."We also have 10 Test matches until the Ashes start in 2027, so whilst we have a significant amount of time to prepare for that with a new coach coming in, we want to use as much time as we have available."England men's managing director Rob Key said some of England's most memorable moments in recent history had occurred during McCullum's tenure."It's been an absolute privilege to watch him shape the mentality of the team, to one the players have loved, and see him develop a new generation of talent who will be at the heart of England men's teams for years to come," Key said."He leaves the Test team well-set and poised to achieve great things." Noting McCullum's England T20 team had recently become the number-one ranked side in the world, the ECB said the search for a new Test coach would now begin.Former Australia captains Justin Langer and Ricky Ponting have both been touted as possible England coaches in the past, while a second stint at the helm for Zimbabwean Andy Flower would also be a popular option.AAP