Ed Miliband has suggested his attempts to strike a less confrontational tone at Prime Minister's Questions have been hampered by the oppositional "cauldron" of the House of Commons.
The Labour leader said he backed Speaker John Bercow's call to curb the "yobbery and public school twittishness" of PMQs to show that MPs can behave better than children.
Asked whether he was trying to strike a more serious and less adversarial tone at PMQs, Miliband said it was possible to disagree "without being disagreeable", quoting US President Barack Obama, but admitted changing the nature of the weekly Commons session was easier said than done.
He told BBC Radio 4's The World This Weekend: "I think it was President Obama who said you can disagree without being disagreeable and in a way maybe that's a sort of lesson for Prime Minister's Questions.
"But it's easier to state and harder to execute. The cauldron of the House of Commons is not conducive to the kind of atmosphere that that invites.
"But we should always endeavour to do it, we should endeavour to be proud of the show we put on for the country and not giving people a sense that you know their kids behave better than we do."
He added: "It is incredibly hard to change. It's the oppositional nature of the House of Commons which is one of the important things about the House of Commons and the accountability of the Prime Minister to the House of Commons in Prime Minister's Questions is really, really important and I think is an essential part of our democracy for all its ills. That doesn't mean we shouldn't try and change it."
The Opposition leader also claimed his plans to reform the Labour Party involved the "biggest change probably since the Labour Party was founded as a membership party in 1918".
The package, which will be voted on at a special conference on March 1, will change Labour's links with the trade unions and allow people to have a say in the party's leadership contests without being full members.
Under the plans, for £3 people can have a vote in the party's leadership elections and involvement in the movement as registered supporters or, for trade union members, affiliated supporters.
Miliband said he hoped membership numbers would now reach levels last seen when Tony Blair was leader and the party won the 1997 General Election with a landslide and had 400,000 members.
He said doing so would re-engage people and "square the circle" between what happens in people's everyday lives and politics.
Miliband said: "Part of the problem is people think politics is just something alien, something not to do with them. And by having more people in from more walks of life you change that.
"People may be turned off political parties but they care about the things around them and what's happening in their own life and this is the way we square that circle."
He went on: "It's not just organisational. I think if you're for big ideals which I think we are, the big causes like child poverty, like the cost of living crisis, like climate change, I think you will come to us. And if you show the difference you can make.
"I don't think people are turned off the idea that they want to change things, they do care about changing things, they are turned off political parties and that's what we've got to change."