Pair programming and unit testing

Question

My team follows the Scrum development cycle. We have received feedback that our unit testing coverage is not very good.

A team member is suggesting the addition of an external testing team to assist the core team, but I feel this will backfire in a bad way.

I am thinking of suggesting pair programming approach. I have a feeling that this should help the code be more "test-worthy" and soon the team can move to test driven development!

What are the potential problems that might arise out of pair programming??