Wallaby rugby great George Smith has hailed England's "winning mentality" ahead of the opening game of the three-Test series in Australia.
The 35-year-old, who has been outstanding for Wasps in the Premiership, has helped England with their breakdown skills under Eddie Jones.
And the flank admits to being impressed with their mindset after winning the Six Nations, with a mouth-watering series awaiting Down Under.
"England are a form team generating a winning mentality," he told BBC Sport.
"They are Grand Slam Champions and they've got players who were part of the (Saracens) Champions Cup winning team, while there were three English teams in the semi-finals of the Champions Cup.
"You win some games, and your confidence grows, you win some more and your confidence grows, and you become a team that feels invincible."
However while he is impressed by England, Smith was quick to make it clear who he will be cheering for when the series starts in Brisbane.
"I'm supporting Australia, they're my home country," he told BBC Radio 5 live.
"I'm looking forward to the series, and I'll be there watching in Australia, and cheering the Aussies on."