Sir Menzies Campbell has arrived for his first conference as Lib Dem leader - a week set to feature major debates on taxation and the environment.
Sir Menzies is preparing for his first party conference as leader
As party members gathered in Brighton, Sir Menzies indicated his predecessor Charles Kennedy would be welcomed back to the front bench when "ready".
But he denied he would be upstaged by Mr Kennedy's address to delegates.
Meanwhile, Chancellor Gordon Brown has rejected Sir Menzies' criticism that he was geared towards centralisation.
The approach was unlikely to change if Mr Brown was prime minister, the Lib Dem leader said.
Sir Menzies wants to ditch the commitment to a 50p top rate on incomes over £150,000 in favour of "green" taxes - but some Lib Dems will use the conference to try to keep the policy.
He said: "I believe that if we are to fulfil the objective of substance and not symbolism the package as a whole should be adopted.
"We should not feel compelled to retain something that's become symbolic against the background of the redistributive nature of the package as a whole."
Sir Menzies said the conference would see "robust, full-blooded debates".
He said: "We're going to demonstrate in these debates that we're willing to take the tough choices which are necessary."
Mr Kennedy, who stepped down as leader when it was revealed he had a drink problem, could yet make a "remarkable contribution" to the party, Sir Menzies said.
"He is a man of immense ability and he is a man for whom the party has a great affection and it is an affection that I share... When he is ready I will be happy to welcome him back to the front bench."
In an interview with the Guardian, Sir Menzies was doubtful whether Mr Brown would be much different if, as expected, he takes over from Tony Blair.
He said: "There is no reason to suggest a Prime Minister Brown would depart from the centralisation and authoritarianism which we have seen."
He also said the chancellor's means-tested working families tax credit had hit poorer people.
However, rejecting the criticism, Gordon Brown said he had given the Bank of England independence "the minute" Labour had come to power.
Mr Brown, in Singapore for a G7 summit, added: "I gave up powers so the Bank of England can set interest rates, and I think that is the shape of some constitutional changes that perhaps the Liberals will come eventually to support.
"And therefore I think the record of this government is devolving power wherever it's possible, and the record certainly of the Treasury is to devolve power".
Sir Menzies said the chancellor had a "statist" approach, and added: "I wonder whether the prime minister, left to his own devices, might not have taken a different one."
Commenting on the working families tax credit, he said: "That is dynamite. That is wrecking their lives.
"How many hundred days is it since the chancellor himself answered any questions about it? He must take responsibility."