Former England batsman Geoffrey Boycott has called on team director Andy Flower to make a quick decision on his future.
Flower, who took charge in 2009, has presided over England's Ashes defeat in Australia, with the first chance to regain the urn not until 2015.
"We should be thinking and planning for 2015. Is our coach up to it?" said Boycott, who played in 108 Tests.
"Andy Flower, are you going to be here next year? Are you staying or going? If you've had enough, go now."
Zimbabwean Flower led England to their previous three Ashes triumphs but concerns over his workload eventually led to Ashley Giles taking charge of the limited-overs teams in November 2012.
After England's 150-run defeat in the third Test in Perth, which gave Australia a 3-0 lead with only two Tests to play, Flower was asked about his future but would only comment on the upcoming matches in Melbourne and Sydney.
"We have two Tests and I am hungry to do well in those games," said the 45-year-old. "That is as far as I am looking at the moment."
As well as the three Ashes triumphs, Flower also led England to the top of the world Test rankings in 2011 and the World Twenty20 title in 2010.
But, after three heavy defeats in Australia brought the Ashes defence to the quickest possible end, Boycott believes Flower and his staff must take some responsibility for England's shortcomings.
"Some of our coaching staff should have a serious look at themselves because we are on the down and Australia are on the up," added Boycott, who scored 8,114 runs in Test cricket.
"Australia have had more energy, looked up for the challenge. They have plotted and planned better."
But England captain Alastair Cook defended his former Essex team-mate, insisting he wants Flower to continue.
"He's an outstanding coach, let's make no mistake about that," said Cook.
"He's an outstanding person, and a great person to have around - especially for me as a captain, the advice he gives me.
"It's not down to him that we've lost, it's that we haven't had enough players in form."
Cook was part of the England team that lost 5-0 down under in 2006-07 and Australia captain Michael Clarke has said he is targeting a repeat of that result.
Though Cook is convinced his team can avoid another whitewash, Boycott disagrees.
"It will be 5-0," said the former Yorkshire batsman. "I don't see how they have the mental attitude to pick themselves up. I don't see what will change.
"I've seen it happen before, once you get down there at the bottom it is very difficult to get out.
"This isn't a poor team, they are not poor players, but they are not mentally there."