Our 3-0 is better than yours.

That’s the taunt from paceman Peter Siddle as Australia aim to complete their domination of England in this Ashes series.

Australia go into the Boxing Day Test at the MCG with the Ashes regained and an emphatic 3-0 series lead.

Now they are looking at this year’s two Ashes series as one combined contest where the current score is 3-3 with two to play.

Siddle said on Monday that there was a contrast between England’s 3-0 home series win and how the Australians have dominated over the last few weeks.

“It wasn’t as comprehensive as it looks,” Siddle said of the English success.

“Compare that 3-0 to this 3-0, it’s a total difference.

“A lot of credit has to go to how we’ve played – we’ve been ruthless.

“We haven’t given them anything to jump on the back of.”

The constant message from the Australian camp ahead of Boxing Day is two-fold – they have no interest in commenting about England’s problems and there is no way they will let up.

“It’s their change rooms, isn’t it,” he said.

“It’s not our change rooms (and) all I can speak for is us.

“I know one thing – obviously we’re all good mates in our rooms, we’re happy about the way we’re going.

“We’re in a good place, but we don’t want to let up.”

Ryan Harris continues to appear proppy as he nurses a knee problem, but Siddle is confident his fellow paceman will be fit for the fourth Test.

“Ryan Harris looked like that before the first Test,” Siddle said.

“I don’t think it matters … he’s always going to look like that.

“He’s 34, obviously he’s battled a lot of injuries.

“But he pushes through.

“It’s a positive when he’s like that, because he probably pushes through a bit harder.

“He’s feeling fine … everyone is just looking forward to getting out here now.”

Meanwhile, Australian bowling coach Craig McDermott has praised his attack as the best in Test cricket.

McDermott expects no changes for the Boxing Day Test to the quartet that has bowled so well in this Ashes series.

“They’ve all performed as a unit fantastically well,” McDermott said.

“We have the best attack in the world at the moment.’