Alastair Cook has admitted the idea England can win the World Cup is "a bit far fetched" but insisted he has no plans to step down as England's ODI captain. England were thrashed by nine-wickets by India at Edgbaston with almost 20-overs remaining, sealing a 3-0 series result with one match to come.

It meant England had lost their last five ODIs in succession and five series out of six. The single series victory, in the Caribbean, came when Cook was not in the team.

With a maximum of 13 matches to go ahead of the World Cup, England are running out of time to find a viable plan to render them competitive - a view now officially sanctioned by a captain who has virtually written them off.

But while Cook, who has now not reached 80 in an ODI in 38 innings and 26 months, admitted to some doubts about his own form, he remains convinced that England's strategy remains correct and that he can play a part in turning around the disappointing run of results.

"I've captained for three-and-a-half years with the goal to try to win the World Cup in Australia," Cook said. "I know that seems a bit far-fetched at the moment but there's a lot of really good players in that changing room and if we can improve at the rate we need to improve we've got a chance. That's what we have to believe.

Any team that improves at the rate it needs to would, by definition, automatically become champions.

Cook insisted that his doubts about his own performance were ever present. "You always have those doubts and I've had those doubts for 80 games and 100 Test matches. You always are trying to prove that you're good enough and trying to contribute runs for an England win. That's the ultimate aim as a batter and at international cricket you're tested every single day, There's always doubts, that doesn't change.

He insisted that he had no plans to quit. "At this precise moment in time, no. I don't have a say on selection, but if I'm allowed to be, yes, I'll be at the World Cup. If not, then I have to take that on the chin. I hope not, but if it is, it is.

"I believe at the top of the order that, if I bat for 40-odd overs, I will score enough runs at a good rate. That's what I have done when I've been batting well."

The reference to 40-odd overs suggested that Cook was putting his own emphasis on an ability virtually to bat through the innings, which sounded dangerously close to all or nothing.

While Cook admitted the poor run of results had done nothing for the confidence in the dressing room, he suggested it was more due to poor execution of skills than poor tactics.

"Maybe for a few of these guys, it is the first time that we've lost as badly as this," Cook said. "It is a true test of character for the whole team, really.

"We don't quite know our best 11 at the moment because the results are showing we're not performing. When that happens you always start to doubt. That's the position we're in at the moment. We've got six months of one-day cricket to try and put that right.

"I don't think our strategy does need to change. I just think we need to do it better. The first two games we got really good starts off the first 10 overs and the problem is none of us have gone on.

"It's been our lack of execution of fairly basic skills at the moment with our batting. As a one-day batter, you need to be able to score at a good rate, at certain times take low-risk shots for a while but have the option of putting the pressure back on the opposition but also staying in. Unfortunately, we're not doing that.

"But it's amazing how quickly you can turn around. We've got to stay true to our beliefs as a team and actually the belief you have as a player because when you lose games of cricket people chip away at you and you start doubting the reason why you probably got selected in the first place."

While some have claimed that England are suffering in the shorter formats partly because their priority has often appeared to be Test cricket - this season is the first in which domestic cricket has been played over 50 overs for many years and in the past key players have been rested from limited-overs sides with a view to keeping them fresh for the Test side - Cook dismissed the theory.

"You only have to look at the dressing-room now to see whether it matters or not," Cook said. "We're brought up in a country where Test cricket has huge importance. But just because you put huge importance on Test cricket doesn't mean one-day cricket doesn't count.

"We've got a World Cup in six months. That's our big focus now. There is no Test cricket for six months, so it is very important."

George Dobell is a senior correspondent at ESPNcricinfo