England coach Trevor Bayliss claims Australia are "far from stable" two months out from the first Ashes Test.
Bayliss has watched his team secure series victories at home to South Africa and West Indies in recent months, while Australia had to recover from a shock opening defeat to draw 1-1 away to an improving Bangladesh side.
The first Test between the two fierce foes begins on November 23 in Brisbane, where the visitors will be determined to make amends for the humiliating 5-0 whitewash they suffered in 2013-14.
"We are not going over to make up the numbers," Bayliss said.
"We are going to leave here with a view to win, simple as that.
"One thing this group has got is plenty of fight and character and I think our opposition in the Ashes is far from stable."
Questions remain over several of England's key batting positions, with opener Mark Stoneman, first drop Tom Westley and number five Dawid Malan all yet to fully convince.
Of the trio, Bayliss said: "[They] have shown that they are good enough but are they good enough for long enough? Are they tough enough? Especially for an Ashes series.
"We will be discussing other players that we have had in the team over the last 12-18 months but these three guys - it will be hard to go past them, put it that way."