The deputy prime minister will single out those with "unearned wealth" as well as Russian oligarchs at the start of his party's annual conference in Brighton.
Later in the week the party will announce that Scots will have paid more than £1 billion less in income tax thanks to the LibDem campaign to raise tax-free allowances.
Last month Mr Clegg called for an "emergency" wealth tax to avoid social strife. But his party has faced criticism for being part of a Coalition Government that announced a tax cut for millionaires this year.
Amid speculation over Mr Clegg's leadership future and disastrous poll ratings, the LibDems are keen to focus on taxes and move on from the ridicule that surrounded his apology over university tuition fees.
Last night Mr Clegg insisted he had no regrets over saying sorry despite the video apology being widely lampooned.
He said it was inevitable people would "sneer" and "mock" but defended the move as the "right thing to do".
Today he will say it is wrong ordinary people "are taxed so much" while billionaires "pay the same council tax as some people do on a family home".
He will insist his party has different priorities to the Tories and is fighting for "lower taxes on work and more on unearned wealth".
"I want to reward people who put in a proper shift, not those who sit on a fortune," he will say as he calls for further action to raise the tax-free allowance towards the party's target of £10,000.
Scottish Secretary Michael Moore will tell conference Scots will have paid £1.2bn less in tax by next April thanks to the Coalition's decision to raise the allowance.
It means 162,000 Scots on low to middle incomes will have been taken out of the tax system. The £1.2bn is in cash terms; when inflation is taken into account it is £735 million.
"That's a huge amount. That to me is a massively important issue," Mr Moore told The Herald.
"Next year, people will be getting £500 a year more in their pockets as a result of these measures than would have been otherwise. That's something people recognise as having been a core LibDem contribution to the Coalition."
Mr Clegg's speech will be seen as a further signal that his party is moving towards plans for a wealth tax. They are understood to be looking at a four-pronged approach – one arm of which would include a so-called mansion tax.
Matthew Sinclair, the chief executive of the TaxPayers' Alliance, condemned talk of a wealth tax as "mad".
"Britain does need fairer taxes but that won't be achieved by Nick Clegg attacking people for saving and investing," he added.
"It would be madness to repeat the mistakes of other European countries where they have already discovered that wealth taxes are an economic disaster.
"Even if politicians can wring more money out with even higher taxes on people's homes or pensions, it won't be anything like enough to allow for significant cuts in taxes on income."
Mr Clegg will also claim "an economic catastrophe" has been avoided despite the second recession in five years and will emphasise how much his hands are tied as the leader of the junior Coalition partner.
The LibDems have set "fairer taxes" as their theme for the conference. Party strategists are keenly aware they get little or no credit from the public over the rise in tax-free allowances.
Instead they believe it has been overshadowed by George Osborne's Budget announcement that he was scrapping the top 50p rate of tax.
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