Under-siege England remain a serious World Cup threat despite being on the verge of an embarrassing pool-stage exit, according to Wallabies coach Michael Cheika.

The host nation will be eliminated from their own tournament should they fall to Australia in Saturday’s vital Pool A match at Twickenham.

It will prove crucial too for the Wallabies, who would face an uphill battle to reach the knock-out stages should they lose to England due to their failure to land a bonus point in their tournament-opening win over Fiji.

Pressure is mounting on Stuart Lancaster and his men to respond following Saturday’s shock 28-25 loss to Wales – a defeat that ended with a controversial decision by captain Chris Robshaw to push for a match-winning try, rather than a score-levelling penalty goal.

But Cheika wasn’t buying into any theories that England are a beaten team, saying they’re no less a threat than they were when bookies installed them as second favourites behind the All Blacks two weeks ago.

“They were the second favourites behind New Zealand at the start of the tournament and I don’t see just because they lost a game that should change,” he said on Monday.

A major factor behind Cheika’s belief that England remain one of the tournament heavyweights is the undeniable advantage they get from playing at Twickenham – one of the more hostile away venues in world rugby.

“They are playing at their home ground, number one, where inevitably they win,” Cheika explained.

“It’s already a difficult challenge playing a team in the World Cup in their home venue.”

Cheika also pointed to England’s recent dominance over the Wallabies as cause for concern.

England have won four of the past five encounters between the two nations, including a 26-17 victory at Twickenham last year on Cheika’s first tour as head coach.

On that occasion, Australia’s dangerman Israel Folau was kept quiet and their weakness in the set piece was exposed – a point Cheika has not forgotten.

“We weren’t bad in that game, but being not bad is not enough,” he said.

“Since that tour, we have been trying to improve a lot in lots of areas of the game.

“Some of it we have and some we feel we have more to improve.

“We haven’t been a year together since that tour.

“They are going to be a pretty formidable opponent, there’s no doubt about that.”

Meanwhile, England’s code-hopping star Sam Burgess has been criticised for his performance in the Wales loss, and faces pressure to retain his spot for the Wallabies clash.

The former South Sydney star spoke to Cheika prior to making his code-switch at the end of last year and has exceeded most expectations by reaching, and impressing in, the World Cup after less than a year in the game.

“Obviously I am a big fan of his, from his rugby league days as well,” Cheika said.

“But I don’t know (whether he’ll keep his spot). I am sure whatever they do it will be difficult to deal with and we will have to find the answers.”