As told to Anoosh Chakelian.

We don’t have an effective opposition. The question is how to make it effective. I think they should start to discuss with a view to deciding at a conference this summer on its policies. It’s just got to stop for a moment, have a pause on personalities. They’re going to have to return to personalities, they have to have a new leader. But at the moment, the issue should be: let’s get the policies right. I’m sure there are areas in which people want to see changes, but they’re obviously completely incoherent over Europe, so just let that incoherence lie.

If Labour party MPs can’t start to talk about why young people were attracted to Jeremy Corbyn, they won't find the solution. Corbyn – you can trash him like the right-wing press do every day, but they've always done that with every form of Labour leader we've ever had. I’m not defending Corbyn, I don’t think he is the right person to be leader of the Labour party and become Prime Minister.

They've got to widen their base, and they've got to widen it in an election. That doesn't stop the party having more values. The Labour party instinctively, like the country, needs to move a bit more to the left. I'm not afraid of talking more about socialism and social values. I think that would be matching the mood of the country.

Clement Attlee and the Labour party came in in 1945, and shocked everybody, including all the pundits and newspapers – they responded to a mood in the country that wanted a difference. I believe there is a mood in the country that wants a difference. They don’t want recycled Blairism.

You’ve just got to face up to reality. The fundamental thing is, where we slipped up in [the last] election, is that we were not able to answer the question – when they were ravaged and savaged about the SNP – Ed Miliband should've lost his cool. All he said during the attack about working with the SNP was that it ain't going to happen. Well, it obviously was going to happen.

What they needed to say is proudly and completely coherently: if the electorate send a Parliament back which has the SNP in substantial numbers, it is perfectly legitimate for the Labour party to work with them. Health policy – a pretty good step would be to take what’s happening in Scotland and more or less mirror it.

That is the nature of the beast, which is democracy. Even without changing the system of voting, we now have multi-parties, whether we like it or not. We were told the route through was not to create a Social Democratic Party alongside the Liberals, you had to merge with them and that there was no room for more than three political parties in Britain. Well, it’s absolute nonsense. We now have seven, you could argue. We have to live with that reality. You have to be ready to talk to them. You won’t agree with them on separation but you can agree on many other areas, or you certainly should be trying.

I think it’s asking a hell of a lot to be leader of a party, asking to be Prime Minister, when you've never performed yourself in government, you've never held a serious job anywhere else. It's a very, very big thing. He didn't want to be leader of the party, he didn't expect to be leader of the party, he stood on the basis that he was the person they all turned to on the left, and he did it, and he surprised us all. The fact that he won should be a serious message to us. The reason he won is because everybody was totally sick and fed up with the other people. We've got to face up to the fact that this has happened now twice. Is the Labour party going to go on churning out a sort of mollified form of Blairism?

David Owen is an independent social democratic peer and co-founder of the SDP.