Ed Miliband said he wants to subject himself to a regular interrogation by ordinary voters at Westminster if he becomes prime minister.
The Labour leader said inviting public critics to directly confront the country's political leader in Parliament would help re-engage citizens.
He is to submit proposals to Commons Speaker John Bercow amid wider calls to reform the much-criticised weekly Prime Minister's Questions sessions where the premier faces MPs.
If they are approved, a group of voters would be invited to Parliament as often as once a week to have their concerns addressed by the premier.
"I think what we need is a public question time, where regularly the prime minister submits himself or herself to questioning from members of the public in the Palace of Westminster on Wednesdays," Mr Miliband told BBC1's Andrew Marr Show.
"Why is that important? Because I want to let the public in to our politics.
"At the moment there is the glass that separates the public in the gallery from the House of Commons, but there is a gulf miles wide between the kind of politics people want and what Prime Minister's Questions offers."
Labour said that the sessions would happen at least once a fortnight and possibly weekly, if they were given the go-ahead by the Speaker.
Questioners "would be chosen by a method to ensure a wide representation of the country and political backgrounds", a spokesman said.
Mr Bercow's office said it would examine any proposals submitted by the Labour leader - which it said echoed similar reforms already submitted to a review.
"The Speaker will look at Mr Miliband's suggestions with interest, when he receives them. Clearly, any changes would be a matter for the House," his spokeswoman said.
"The Speaker's special Commission looking at the effects of the digital revolution on our democracy has received similar suggestions from people outside Parliament.
"However, it is clear that within Westminster there is also an appetite for further reforms to the way the House of Commons conducts itself."
Number 10 said that Prime Minister David Cameron " is open to new ways of engaging with the public" but pointed out that he already held regular "PM Direct" sessions.
They take place in a variety of locations around the UK and are an extension of the open town hall "Cameron Direct" meetings which he pioneered as leader of the opposition.
Labour MPs have criticised the cost of holding the sessions.
Mr Miliband earlier this week sought to fight back against critics of his leadership and "geeky" appearance by insisting principles and ideas are more important in politics than style and image.
He denied his latest initiative was a "gimmick".
"It is serious. I want to find ways to change our political culture. It's not just about photo-ops - that is a problem - it is deep and it goes well beyond that," Mr Miliband said.
Mr Miliband said he had spotted the potential for benefit when Deputy Prime Minister Nick Clegg announced he would take part in weekly phone-ins on LBC radio which began in January last year.
Tory London Mayor Boris Johnson and Labour's deputy leader Harriet Harman also now field listeners' queries regularly on the commercial network.
"He got a whole load of bile about it when he did it and I remember saying to people 'actually, it's a good thing to do'.
"I will do that in terms of radio phone-ins but I want to do more."
He defended his decision to seek a chance to speak directly with US President Barack Obama last week - rejecting suggestions it had been an example of the sort of "trivial" politics he criticised.
Mr Obama made an informal but orchestrated appearance during a meeting between Mr Miliband and top US national security officials at the White House.
"As somebody who wants to be the prime minister of the country, I think that for me to engage with the president of the United States is a totally sensible thing," he said.