Voters should be given free shares in state-owned banks so they can benefit from the sell-off of bailed out institutions, Nick Clegg has said.
The Deputy Prime Minister revealed that he had urged the Treasury to adopt the scheme as he criticised the Conservatives for not being tough enough with the City.
In a direct echo of David Cameron's complaint that the Liberal Democrats were holding him back on immigration and welfare, Mr Clegg said he would have been "much tougher".
And, talking to reporters during a visit to Brazil, he revealed that he had this week written to Chancellor George Osborne pushing the creation of a "people's banks" scheme.
A blueprint developed by a City firm would see all 45 million people on the electoral roll handed most of the state's shareholdings in Royal Bank of Scotland and Lloyds Banking Group.
The taxpayer owns 83% of RBS and 41% of Lloyds after the Government pumped in around £65.8 billion in 2008 at the height of the financial meltdown.
A "floor" price would be set below which the shares could not be sold to ensure the Treasury at least broke even - with individuals able to benefit from future growth.
That price is estimated at 74p for Lloyds and 51p for RBS shares. Given sharp falls in the share price, it could be some time before a profit could be realised.
Mr Clegg said that as taxpayers' money had been used to put the banks on a life-support machine, it was important they were given a stake and some future influence.
"Psychologically it is immensely important that the British people feel they have not just been overlooked and ignored," he said.
"Their money has been used to the tune of billions to keep the British banking system on a life-support machine and they have absolutely no say at all in what happens when normality is restored.
"I think, in a sense, as a society we are condemned to take an interest in our banking system."
He went on: "You are giving the Treasury an assurance that they will break even but you are not giving the Treasury the freedom to grab the windfall if there is one.
"This is something I have discussed a lot with (Liberal Democrat Business Secretary) Vince (Cable). Vince and I feel it is something that we want officials to look at."
There remained "a huge amount of detail still to be worked on", he conceded. Critics have suggested the scheme would be unworkably complex.
City firm Portman Capital produced the idea in March - with the support of the Lib Dem Treasury Parliamentary Committee, chaired by backbench MP Stephen Williams.
"David [Cameron] has said he is keen to look at it so there is a real willingness in Government to look at these model ideas," Mr Clegg said.
Mr Clegg sees banking reform as an area in which he can demonstrate Liberal Democrat muscle within the coalition as he seeks to recover from May's disastrous election results.
In a tit-for-tat retaliation to Mr Cameron's complaint earlier this week, he said: "I am absolutely convinced if the Liberal Democrats were alone in the government you would have a much tougher approach towards banks."
A Treasury spokesman said: "While the question hasn't arisen at the moment, we've said we shall look at all options".
Chancellor George Osborne used his annual Mansion House speech last week to insist it was time for the taxpayer to "plan our exit" from the sector, starting with the sale of Northern Rock.