Tom Harrison, the ECB chief executive, has effectively ruled out the scheduling of a day-night Ashes Test when Australia tour England in 2019, despite the concept's success in drawing bigger crowds to grounds and greater audiences to television screens.

Alongside Cricket Australia's chief executive James Sutherland, Harrison has been a key advocate for changes geared at making Test cricket more accessible to fans, with day-night matches, the looming Test Championship and experiments with four-day matches among the measures being tried around the world.

However Harrison was firm in stating it was highly unlikely that a day-night Ashes Test would be part of the 2019 schedule, arguing that England hosting Australia did not need tinkering with. The two countries played a first day-night Test against each other in the second match of the current series at Adelaide Oval, and Sutherland has indicated there will now be at least one floodlit Test in every Australian home summer. Two day/night fixtures - against India and Sri Lanka - are likely in 2018-19.

"It's to be decided, but it's unlikely, to be honest," Harrison told ABC Radio when asked about the prospect of a day-night Test in 2019. "I think we've got a format that works brilliantly well for us in Ashes cricket in the UK. Right time, right place, right conditions are the rules for day-night Test cricket, I think we'll wait and see, but it's unlikely I would say."

The ECB and CA have taken contrasting approaches to growing the game in recent years, with England's cricket audience reduced by the Board's 12-year-old reliance on Sky television money while Australian cricket chases the widest possible free-to-air television audience. Harrison said that it was "astonishing" to see a crowd of more than 88,000 spectators at the MCG on Boxing Day, but said much more needed to be done to ensure the health of Test cricket around the world.

"It's an astonishing achievement to get this amount of people watching Test cricket and it's a great advert for where we are as an Ashes series, but of course the Ashes is not the standard marker for what Test cricket is actually facing around the world," Harrison said. "So we've got to take a look at that, James and I are involved in a similar debate at ICC about how we make sure that Test cricket is relevant, it has context and meaning and the conditions under which it is played can guarantee as much as possible fantastic entertainment for fans around the world.

"I think there are significant challenges there, but I think we're doing the right thing by looking at the FTP in a meaningful way, trying to create a Test Championship around the FTP, which we're very close to doing. Once you've got a Championship format where every series matters we can start looking at the details that sit behind that.

"About pitch quality, about the schedule itself, about the way in which we can start innovating beyond things like day/night Test cricket which has worked so well in this country and we've just started in the UK as well, and start to look at what are the key things we can tweak within Test cricket to make it even more relevant and meaningful for fans."

The Melbourne crowd thinned out significantly by the end of Boxing Day, and the slow drop-in pitch has already faced criticism - from the England seamer James Anderson among others - for not providing the right sort of entertainment for spectators. Sutherland said that while Test cricket would inherently contain such passages, it was vital that good, fair surfaces were prepared to provide a balance between bat and ball.

"It was a dour day's play, Australia got off to a pretty good start and then England were able to contain the Australian players through that middle session," Sutherland said. "That was perhaps a little bit due to the conditions but also good bowling on the England players' part. But Test cricket's like that sometimes, it's a real battle and players need to work through those difficult times. I think it's too early to judge in this Test match what that means and people talking about the pitch and things like that.

"I think the broad statement is pitches are incredibly important to the future of Test cricket, we need to provide an entertaining contest, we need to provide a balance between bat and ball and I think broadly we've seen that in the three Test matches so far this summer, and who knows, there's still four days' cricket left in this game, let's see how everything unfolds on the park."