The England and Wales Cricket Board has unveiled plans for their new eight-team domestic competition to use a new format of 100 balls per side, rather than 20 overs.

Under the new proposals, the eight city-based men’s and women’s teams would play 15 regular overs, followed by a final 10-ball over. Matches would be 20 balls shorter than traditional Twenty20 contests.

“This is a fresh and exciting idea which will appeal to a younger audience and attract new fans to the game,” said Tom Harrison, the ECB’s chief executive. “Our game has a history of innovation and we have a duty to look for future growth.”

“Based on 15 traditional six-ball overs, the other 10 balls will add a fresh tactical dimension,” said Sanjay Patel, the ECB’s chief commercial officer. “Crucially, this will also help differentiate this competition from Vitality Blast and other T20 competitions worldwide.”

The unexpected announcement has led to a backlash on social media. The former England captain Michael Vaughan tweeted “cricket now has five day, four day, three day, two day, 50 overs, 40 overs, 20 overs, T10 league, Hong [Kong] sixes and 100 ball comp... Good luck understanding our great game!”

Speaking to Sky Sports News, the England bowler Stuart Broad defended the plans. “I’m hugely optimistic,” he said. “I love the fact that it’s different to all the other tournaments worldwide – 15 six-ball overs and then the pressure of a 10-ball over to finish.

“I love the fact it’s got a slightly different unique selling point in there, a shorter game than T20, finishing at 9pm – perfect for children and families and a great night out.”

Last year, the ECB announced a £1.1bn broadcast deal with Sky and the BBC, with 10 games from the new tournament to be shown live on terrestrial television.

Lord’s and the Oval are expected to host separate teams with Southampton, Birmingham, Leeds, Manchester, Cardiff and Nottingham also selected as venues for the five-week competition, which starts in 2020.