Nick Clegg told Welsh Lib Dems he would "bake" fairness into tax
Liberal Democrat leader Nick Clegg has told his Welsh party conference that in the wake of the MPs' expenses scandal this has been the "rotten Parliament" .
Mr Clegg said people would be "appalled" by MPs claiming the protection of parliamentary privilege.
He told Lib Dems in Swansea he wanted a "fairer Wales", arguing the wealthiest should pay more to help raise the income tax threshold to £10,000.
That would mean more than 200,000 in Wales no longer paying tax, he said.
It would also hand back £700 to 800,000 more, he argued.
On the expenses affair, he told the BBC: "Lawmakers shouldn't be above the law and they should not be invoking 17th Century conventions in order to avoid paying their expenses."
Mr Clegg said Britain had a "rotten system of party funding", and alarm bells should be ringing about "a political culture where more people didn't vote in the last two elections than voted for the winning party".
Mr Clegg told the conference that his party's "vision for Wales has fairness at its heart".
He told members that under his plans, the first £10,000 that people earn would be free of tax.
"Low local wages mean Wales will benefit more than most places," he said.
"Hundreds of thousands of people here will no longer pay income tax at all, and hundreds of thousands will get £700 back in their pocket."
Mr Clegg said the best off should should pay more into the "common pot" to help raise the income tax threshold to £10,000.
That, he said, would lift more than 200,000 people in Wales on modest incomes out of paying tax altogether and hand back £700 to 800,000 more.
Mr Clegg acknowledged the tightness of public finances , but said: "Fairer taxes can be paid for if we ask people at the top to pay their fair share.
"And that's why I don't apologise for proposing that the banker from the City of London pay the same rate of tax on his capital gains as his cleaner does on her wages.
"It's right that people who live in very big properties, mansions worth £2m or more, should pay a bit of money, put it into the common pot so we can raise the tax threshold to £10,000.
"That is fairness. That is fairness baked into our tax system.
"Labour should have done it. They haven't. The Conservatives never will. Plaid can't. We will."
Mr Clegg also outlined his party's commitment to further devolution ahead of Tuesday's so-called "trigger" vote in the Welsh assembly on a referendum on further powers.
"The Liberal Democrats have constantly called for real devolution, giving Wales equal status with Scotland by transferring full law-making powers to the assembly," he said.
It emerged on Friday that an agreement has been reached which means all four parties will now support the trigger vote.
Both the Lib Dems and the Conservatives and Liberal Democrats had been threatening to abstain over their concerns that the referendum could be held on the same day as the next assembly election in May 2011.
However, assembly government sources have made it clear that those concerns would be recognised.
The vote next Tuesday will be drafted to facilitate a "trigger" for the referendum process.
Kirsty Williams, leader of the Welsh Lib Dems, echoed Mr Clegg's views on social unfairness.
Speaking after Mr Clegg, she told the conference that closing loopholes for big businesses and the very wealthy, and a commitment to make polluters pay is one way the party would raise the money for income tax breaks for low earners.
The Brecon and Radnorshire AM said: "The richest 10% take home more income than the least well off half of society combined. That just isn't fair.
"It isn't right. For decades we have lived in a Wales where it doesn't always pay to work, where unfair taxes strip hard working people of dignity and ambition.
"Welsh Liberal Democrats will not stand by and accept a mediocre future offered by second-rate leadership. We will not stand by and succumb to the despair the politics of the past is responsible for."
"Reject a tired Labour party that is out of ideas and out of touch and a Tory party offering tax breaks for the rich.
"Instead, you can choose Liberal Democrats, the only party offering change that will work for you, in your daily life.
"Fair taxes for all, a fair start for children, a fair, sustainable economy and fair, clean, local politics."