Helen Clark and John Key took each other on with strident determination tonight in the first leaders debate of the election campaign.

The 90-minute TV One head to head was marked by feisty exchanges as they interrupted each other and refused to give ground.

“You’re not going to shout me down, John,” Clark at one stage told National’s fired up leader.

Key gave as good as he got, and at times Clark talked over him as she challenged the points he was making about the economy, incomes, housing and the environment.

Clark managed to get ahead when she used Labour’s record to trash the previous National government’s policies — housing in particular — but Key came back with facts and figures in today’s terms.

Both were well prepared, self-assured and determined not to let the other get away with anything.

Key was strong on the economy and the need to increase prosperity.

And he was right up to date. “The Carter Holt redundancies happened because our economy is inefficient,” he said, referring to announcements made just a few hours before the debate started.

Clark didn’t agree, and she let him know it.

They were well matched in the important campaign event, they both knew their business and there was no way either was going to be beaten.