"I believe England have the raw materials to build another very strong side. The area of concern for me is mental; they need toughening up," Hussain said in an interview for the February issue of The Wisden Cricketer magazine.
Hussain, who captained the side in 45 Tests between 1999 and 2003, was particularly critical of England's batsmen.
"There is a softness about some of the batsmen that is preventing them delivering the big runs. There is a sense that being England players is enough. They feel comfortable in the side and think they have fulfilled their potential," he said.
Hussain, 39, said two forthcoming series against New Zealand were an essential part of the preparation for the 2009 Ashes series in England.
"Back-to-back Test series against a weak New Zealand side give them a chance to get back to winning ways and build for the Ashes in 2009," he said.
England relinquished the Ashes in Australia last year when they were beaten 5-0. They have slumped from second to fifth in the International Cricket Council Test rankings after losing in Sri Lanka late last year.
(Reporting by John Mehaffey; Editing by Miles Evans)
