Chief executive of the England & Wales Cricket Board (ECB), Tom Harrison, has revealed that he is in favour of Test matches moving to a four-day format.

The idea was first proposed in 2003 by Andrew Wildblood, former senior international vice-president for International Management Group, claiming it would lead to more exciting cricket.

The debate has continued since with ECB chairman Colin Graves stating in 2015 that he was tabling proposals to change the format.

Although Harrison was against the idea initially, he later changed his mind, mainly due to the benefits of one less day in the format as well as keeping it relevant and attractive for cricket fans.

"It creates space in the calendar but it's not just about that and not just so we can schedule more," he told The Times. "It's about understanding the benefits from a consumer perspective."

"Can we create a better product by introducing a four-day format in certain conditions? My personal view is that I don't think it works everywhere; like day-night Test cricket, it has to be the right time, right place, right conditions.

"We have to take a look at the pressure on boards to keep Test cricket at the heart of their proposition. We've seen a lot of amazing Tests over five days but we haven't really tested the theory as to whether the players' mindset changes over four — if we increase the over rates, which is a thorny topic. I don't believe it's impossible to bowl more overs in a day."

Harrison believes that with the rise of Twenty20 cricket, there is a risk of Test cricket dying if it simply does not adapt.

"Four-day Test cricket is a really interesting debate and will evolve and I'm sure we will get there in the end," he added. "I had to be convinced because when I started out I was massively against it, but I am for it because with Test cricket there is a risk of us loving it to death. We have to adapt."

With England hosting a T20 tournament in 2020 as well as the rising popularity of privately owned leagues such as the Indian Premier League (IPL) and Caribbean Premier League which overlap the English season, Harrison felt it was necessary to address the current state of Test cricket.

"I am absolutely convinced the game can flourish over three forms," he explained. "The balance between international and domestic cricket will change. We have to be careful about that and that is my fear about private ownership. Controlling private ownership will be difficult and controlling the ambition of very successful tournaments will be difficult."

"Test cricket remains absolutely central to the diet that we put out to our fans every year. We are still filling grounds for Tests and we are still the team that everyone wants to come and play against. A Test series in England is still regarded as the pinnacle for many players from overseas."