Alastair Cook openly acknowledged how a prolonged run of poor form had affected him, after leading England to a superb position in the fourth Ashes Test with a historic double-hundred.

Cook progressed from 104 to 244 not out, the highest score by a visiting batsman at the MCG, as the tourist reached 491-9 on Thursday in reply to Australia's 327 all out.

Joe Root's side now look well-placed to push for victory with two days remaining, as it seeks to restore pride having lost the first three Tests and the Ashes urn.

Read: Cook puts England in control with double century

In an interview with BT Sport, Cook was asked by Michael Vaughan how he had managed to dig deep after a run of 10 innings without a fifty had led many to question his future at the highest level.

"I don't think you do clear your head, because those doubts are always there. I can't just say I put it to the back of my mind - they are there and they've been beating me up for four or five weeks because I haven't been playing very well," the 33-year-old responded.

"You've just got to keep believing. There is some inner confidence in me that I've done it before and I can do it again, while I'm still hungry to do it again.

"Last night [after day two], it was [a feeling of] relief and quite emotional. Today I was quite proud that I came back, got in again and dug deep to get a big one.

"When you've been in the form I've been in and you get the chance to get in on a flat wicket, you're extra hungry to make it a big one. And I suppose, as Goochy [Cook's mentor, Graham Gooch] would say, it is a daddy hundred."

Cook, who has now made five Test double-hundreds, added: "I think last night, it ranked right up there, just because of the way I felt going into the game, kind of had the feeling of the last-chance saloon, really.

"When you're in those positions, to be able to say you dug yourself out of them, you can be quite proud of that. 

"My batting has quite a lot of moving parts to it and all tour I've been struggling to get that rhythm of batting, if I'm brutally honest. I was actually a bit embarrassed by my form, but at least today I've gone on and got a big one."

Cook responded with typical modesty when asked to reflect on the fact he has now passed Brian Lara to move up to sixth in Test cricket's all-time run-scoring list.

"I feel a bit sorry for him," joked the opener, before adding: "That's quite special, isn't it. I can go to bed tonight and be quite proud of those stats."