My agent has requested I a voice of her own, but on a kind of 2:1 ratio with the MC, who I have written in first person and am determined to keep in first person.

Would it look too strange to suddenly go into third person for the secondary character, or would it confuse the reader to have two first person POVs?

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erm, have just notice the massive thread about this down page! oops

Would it look too strange to suddenly go into third person for the secondary character, or would it confuse the reader to have two first person POVs?

It would be clearer to me if the secondary one was in third person, but the risk is that s/he feels slightly more distant from the reader, just by contrast with the int-the-head feel of 1st person. Two first person PoVs is fine too, but you'd have to make it very, very clear what was happening, and someone reading without their full attention might be still be momentarily confused. It helps if they have very strongly characterised and different voices.

Emma

Visual clues, like a different font or a little motif at the start of each section, can also be a help.

Thanks Emma and Kate.
I'm experimenting with a couple of different ideas at the moment to see if it works.