Brendon McCullum said there could be "someone better" to be England head coach if he is not "able to steer the ship". McCullum and director of cricket Rob Key are set to be given the opportunity to remain in charge despite England's dismal 4-1 Ashes series defeat in Australia.

England and Wales Cricket Board (ECB) chief executive Richard Gould is carrying out a "thorough review" into the Ashes tour and will "implement the necessary changes over the coming months". McCullum has held talks with Gould and ECB chairman Richard Thompson. The New Zealander is due to lead England in their white-ball series in Sri Lanka in less than two weeks, and the T20 World Cup that follows.

The 44-year-old said he is "keen" to remain in his job, but it would "depend what changes" are imposed upon him. "I've a firm conviction in a lot of my methods," said McCullum. "I'm not against evolution and not against progress. I encourage that across all sports, not just cricket. And all aspects of life as well. So I'm not against that. However, you need to stand for something. You need to believe in your methods and you need to believe in how you go about things."

Key, McCullum and captain Ben Stokes breathed life into England's Test team when they took over four years ago in the aftermath of a 4-0 defeat in Australia. But the methods that brought 10 wins from their first 11 matches in charge have come under intense scrutiny in Australia. The tourists have been far behind Australia with bat, ball and in the field.

Their preparation has been questioned, including the lack of a full-time bowling coach or a member of staff with a speciality in fielding. Heavy defeats in Australia often result in sweeping changes to the leadership of the England team, a move the ECB hierarchy are keen to avoid this time around. However, the future of McCullum in particular appears to hinge on his willingness to accept the need for change and his ability to enact it.

"Whatever you do in life, you have to have some authenticity," said McCullum. "For me in the job as coach, you need to have an influence over how the environment runs and to be in charge of a lot of those decisions that are made when the pressure is on. So as long as that remains, I'm open to progress. I'm open to evolution and some nipping and tucking, but without being ultimately able to steer the ship maybe there is someone better."

Part of the criticism aimed at the environment McCullum has created are allegations of a drinking culture within the England set-up. England spent the break between the second and third Tests on holiday in Noosa, with players photographed in bars. In the aftermath of England's defeat in the final Ashes Test in Sydney, it emerged Harry Brook had been involved in an altercation with a nightclub bouncer the night before a one-day international in Wellington on the limited-overs tour of New Zealand before the trip to Australia. Brook, the white-ball captain, has been fined around £30,000 and given a final warning over his conduct. The 26-year-old has apologised "unreservedly".

Speaking before the Brook incident was revealed but with full knowledge of it, McCullum said: "Half of our guys don't have a drink to be honest. They'll have a couple of beers every now and again. I think people do that in most walks of life." England went ahead with the Noosa trip despite what happened in New Zealand. Brook, the Test vice-captain, was one of the players photographed drinking in the Queensland beach resort. "I felt Noosa was quite important," said McCullum. "They enjoyed themselves off the field and I don't think they did things to excess, and they were still putting in the work off the field in terms of training, albeit not in front of everyone."

Stokes has said he expects McCullum to be in charge for England's first Test of the home summer, against New Zealand in June. The all-rounder offered his backing to McCullum and said he would give the same view to ECB management if asked. And McCullum said he and Stokes remain aligned in their "vision" for the England team. "We always have robust conversations," said McCullum. "That's why you invest in those relationships on the basis of mates, but also as colleagues. It doesn't always mean he's going to agree with my stuff or I'll agree with some of his, but we commit and support one another and that's how I think leadership works."