'As bad a dismissal as you'll see': Vaughan

England's misfiring top-order has again come under the microscope following another early collapse featuring "as bad a dismissal as you can see in Test match cricket", according to former captain Michael Vaughan.

The hosts remain 2-1 up in the five-match series but concerns over their specialist batters’ ability to handle the moving ball grew on the opening day of the fourth Test in Southampton on Thursday.

England slumped to 6-86 with none of their top four scoring more than 17 before their lower order again came to the rescue, as allrounders Sam Curran (78) and Moeen Ali (40) pushed the total to 246.

The form of openers Alastair Cook and Keaton Jennings has been alarming; between them, the pair have managed 191 runs at 15.92 in this series against India, while England have put on 33 before losing their second wicket only twice in six completed innings.

Jennings lasted just four balls on Thursday before paceman Jasprit Bumrah trapped him lbw not offering a shot in bizarre fashion, a dismissal that led Vaughan to question his place in the team.

"You have to fear for Keaton Jennings' career," the Ashes-winning ex-skipper told the BBC. "When you see a dismissal like we saw this morning – he clearly went out there with a pre-determined mind to leave the ball.

"That was a full-ish ball on leg-stump and it was as bad a dismissal as you can see in Test match cricket.

"That tells me that his mind isn't on watching the ball and reacting to the ball that's delivered. His mind is, 'right I'm going to leave it'.

"Once you get into that position as a batsman, it's very hard to get out of that mindset.

"He'll be certainly looking over his shoulder, as he should be with the way that he's played."

England recalled Jennings, one of the 12 opening partners Cook has had since the retirement of Andrew Strauss, at the expense of Mark Stoneman for the second Test against Pakistan in May. Stoneman and Cook were statistically England's worst ever opening partnership, averaging just 18.75 for the first wicket.

Since making a century on debut against India in Mumbai back in December 2016, Jennings has passed 50 just once in 18 innings and his career batting average sits at 21.94.

England captain Joe Root, himself averaging just 24.33 in the series, backed Jennings ahead of the fourth Test and reasoned that the openers have had to consistently contend with bowler-friendly conditions during the campaign.

"It’s been challenging conditions for the top order, for both sides," said Root. "We’ve got to be realistic about things – we’ve got two very good players at the top of the order.

"We’ve got to go back and find ways to adapt, and that’s not just those two guys."

Another former England batsman, Rob Key, insisted that Jennings should receive at least one more Test (the final match of the series at The Oval) to prove himself before being discarded.

"You could say Jennings looks like a man with a frazzled mind at the moment but India have bowled brilliantly at him," Key wrote in his column for Sky Sports. "(T)he pressure has been relentless, the bowlers have found a bit of swing and it's hard against that new ball.

"You can't imagine he will get out again like he did on day one here, leaving a ball that swung in a mile, as he will be looking to play it next time.

"England's greatest ever run scorer, Alastair Cook, is struggling at the other end so clearly it's not easy – Joe Root has had it tough, too. They've all been skittled out in these conditions.

"There aren't loads of openers knocking the door down."