Stuart Broad believes that Alex Hales has the ability to turn around England's faltering World Cup campaign should the hard-hitting opener get his chance.

Hales has been unused at the World Cup but there have been calls to give him a go as England have so far blundered through the group stage.

Three heavy defeats in four games have left England - who have been unchanged throughout the tournament - needing to beat lower-ranked Bangladesh and Afghanistan or face the unthinkable prospect of an exit before the quarter-finals.

Coach Peter Moores and skipper Eoin Morgan have the best part of a week to decide if they need to make changes before the first of those must-win games, against Bangladesh in Adelaide next Monday.

Hales, who is the third-ranked Twenty20 batsman in the world, would appear the most likely candidate for promotion with the out-of-form Gary Ballance having managed just 36 runs at an average of nine in the tournament.

Broad was not willing to wade into any debate about team selection - his own form is also under the spotlight - but he is an advocate of Hales' enigmatic talents at a time when England need to find inspiration from somewhere fast.

"He's a player who can change momentums of games," Broad said.

"We are looking for players to stand up. (It's) part of being in a World Cup; no we've not got the results we want, but every player in the squad should be quite excited because it only takes a great run out or an amazing catch for the whole momentum of our campaign to change so every player should be thinking 'I can change the momentum of this World Cup'."

Hales' best moments in an England shirt have been reserved for the shortest format.

He proved he can fire at an international tournament when he blasted a memorable century against eventual champions Sri Lanka at the 2014 World Twenty20, but failed to convince when he was then handed his 50-over debut against India in the summer.

The 26-year-old right-hander scored 40 and 42 in his first two games but since then has managed just one score over 10 in five innings.

"He is the sort of player who can get you nought or 140," Broad said.

"He is a dangerous player. That World Cup knock in Bangladesh against Sri Lanka was one of the best you've seen.

"He obviously struggled when he came into the 50-over side a bit, didn't he, in the India series."

Broad denied, though, that he was found out against India, adding: "I don't know if he has technical faults. He has scored six or seven hundreds for Notts in the past two years.

"I like him as a player. He has been a good team-mate of mine and I have watched him play some great knocks at Notts and in T20 stuff, that match-winning 99 against West Indies at Trent Bridge.

"But also I think Gary and (James) Taylor's domestic records are above anyone else by a country mile.

"Gary has obviously not clicked in this World Cup so far but again it is a tough time to come in. He has not played in the Tri-Series and in he comes.

"But fortunately my dream is to be the youngest chairman of selectors there has ever been, but I am not there yet."