When Jeremy Corbyn ran for the Labour leadership, he said that he wanted to change how politics was done. He must have known at the time that by himself he would have little chance of making much headway with that, although that wouldn’t stop him trying. So today at Prime Minister’s Questions, he started to try, and, quite frankly, it worked.

Corbyn stood and said that he had wanted a less theatrical Prime Minister’s Questions with more serious debate, leading David Cameron to agree they should try to focus on more substantial issues. But the ball really was in Corbyn’s court. So it was that the new Labour leader quizzed the Prime Minister on housing, tax credits and cuts to mental health services, with MPs listening in near silence to the exchanges.

The method that Corbyn used was to send an email to Labour Party members and ask them to send in a question. He received 40,000 replies, and he had selected some to read out. Because the questions were thus effectively coming from the general public, Cameron was forced to be far more respectful than he might have been.

Here are some of the exchanges:

1. “From a woman called Marie – ‘what does the government intend to do about the chronic lack of affordable housing and the extortionate rents charged by some private sector landlords in this country'” – Cameron pointed to the 260,000 affordable housing units in the last Parliament and more council house units than 13 years of Labour government, but admitted more needed to be done. 
2. His second question, on behalf of “Steven” was about job losses at housing associations caused by cuts in rent – Mr Cameron said it was “vital” to reform housing associations to “make sure they are more efficient”.
3. The Labour leader then turned to what he called “shameful” cuts in tax credits, voted through by MPs on Tuesday, which he said would cost “£1,300 per year to families affected”. Quoting “Paul”, he asked: ‘Why is the government taking tax credits away from families?” – The prime minister said: “What we need is a country where work pays.”He claimed the lowest paid would get a “£20 a week pay rise next year”
4. Mr Corbyn ended with a question from “Gail”: “Do you think it’s acceptable that the mental health services in this country are on their knees at the present time?” – Mr Cameron said that mental health was one of “the areas where we can work together” and the government had made “some important steps” forward, bringing mental health into parity with physical health in the NHS constitution.But he added: “We will not have a strong NHS unless we have a strong economy, and if the Labour Party is going to go down the route of unlimited spending, unlimited borrowing, unlimited tax rates, printing money, they will wreck the economic security of our country and the family security of every family in our country.”

Now, if I was going to criticize what Corbyn did, I would argue that Cameron was not properly challenged during this session, it was just question answer question answer and I wonder if he was sufficiently held to account. But the lesson from PMQs today is that it might actually be possible for Jeremy Corbyn to change the way politics works – but he will have to do it by his actions, and he will have to do it bit by bit.