Mr Paddy Ashdown has warned the Liberal Democrats against the "easy trap" of a leftward lurch into "oppositional politics".
In his first speech to conference since standing down as leader, Mr Ashdown also warned the party it had become "far too staid" and "conservative" in its approach to the public services - urging them to find new ways to protect the citizen and consumer in an era of globalisation.
His speech was billed "a gentle reminder" to the party to keep its thinking fresh and its ideas relevant. While acknowledging that many of its policies had been implemented, Mr Ashdown said: "In some areas we are, I fear, running the risk of becoming rather lazy and complacent. If we Liberal Democrats will not think afresh, then we risk falling into the easy trap of leftist, oppositional politics." And that, he warned, "would mean making ourselves irrelevant for a generation."
Thinking afresh, he said, meant liberating public services from "the clammy embrace of corporatism" and making them more responsive "to the consumer, not the producer".
He went on: "We have become far too staid, far too conservative, in our thinking about public services. As liberals, our place is to be on the side of the citizen, not the state; of the consumer, not the producer. What matters is not who provides the service but how good the service is."
Mr Ashdown's successor, Mr Charles Kennedy, denied suggestions that the former leader's speech represented a warning from the liberal to the social democratic wing of the party. "No it's not that, I agree with him," said Mr Kennedy: "I think that Paddy and myself are absolutely at one that, with a view to the next general election, the policy-making of the party will have to take account of the changed realities of British politics."
However, Mr Kennedy told BBC Radio 4 the election would be dominated by arguments over what should be done with "the treasure chest of money" now building at the Treasury.
"Should the policy emphasis, as the government seems to want, be on reducing tax for those already best off in society? Or should it be, as we will argue, for enlightened and sensible further investment in schools, hospitals, help for pensioners and so on?"