England's local elections provide an "opportunity to reject New Labour and its mimics", Sir Menzies Campbell said as he launched the Lib Dems' campaign.
Sir Menzies says Lib Dems can compete across the country
He said there were "no no-go areas" of the country in which the party cannot compete with its rivals.
Sir Menzies focused on the record Lib Dem councils have had in cutting crime and on environmental policies.
Labour and the Conservatives are also expected to make law and order a central issue of the campaign.
Elections take place across English 312 local authorities on 3 May, the same day that polls are held for the Welsh Assembly and Scottish Parliament.
Sir Menzies, opening the Lib Dem campaign, said it would be a "disaster" if New Labour remained in power.
He said Chancellor Gordon Brown, expected to take over as prime minister in the next few months, was as responsible for Labour policy as Tony Blair.
"Blair's legacy is Brown's legacy. The mess of tax credits, the intrusion of ID cards, the outrage of the Iraq war. Whether or not the ideas come from the chancellor, the man with the cheques is always Gordon Brown."
He also criticised the Conservative party for lacking clear policies.
"David Cameron's Conservatives have learned all the wrong lessons from Tony Blair - the soundbites, the spin - the willingness to say anything in order to win votes.
"How could the Conservatives make a difference to local government when they cannot tell us what they believe in?"
Sir Menzies pointed to the record of Lib Dem councils in all parts of the UK in dealing with crime and climate change, as well as giving power back to local people.
"Liberal Democrats are not just present on councils in the north and south, east and west, and Scotland and Wales; we are leading them too.
"From the urban north, where the Conservatives are nowhere to be seen, to the rural south, where Labour is all but invisible, there are no areas where we cannot fight.
"The Liberal Democrats are a national party of local government."
Sir Menzies is to visit Woking, in Surrey, to meet a youth theatre group which works with disadvantaged young adults.
Labour is also launching its campaign on Tuesday, saying it has given councils more powers to cut crime and anti-social behaviour.
Meanwhile, the Tories will call for more local control of policing.