Charles Clarke, the former Home Secretary, yesterday warned Gordon Brown that Labour had "wasted" much of this parliamentary term and needed to generate new ideas or face defeat at the hands of David Cameron's Tories, possibly for a decade.

Writing in Progress magazine, the Blairite ex-minister argued that in the first two Labour terms to 2005, many decisions were put off and many reforms not completed.

He said the list of subjects where change was incomplete or had not even been broached included "Scotland and the UK" as well as green policy, welfare reform, party funding, old-age care, trust schools and foundation hospitals among others.

"With some exceptions, our action to make the necessary changes has been insufficient," he said. "And now it seems to me that Labour still remains very unclear about our approach, both in this parliament and the next.

"By now people are entitled to expect Labour to know what works and not to need short-term reviews and pilots."