Today on Kerre McIvor Mornings: What next for British PM Theresa May after a crushing defeat for her Brexit deal; why NZ's hospitality industry is crying out for staff - and how one cannabis joint can alter a teenager's brain structure.

McIvor, a journalist, author and Herald on Sunday columnist, takes over this week in Newstalk ZB's 9am-midday slot from Leighton Smith, who had reigned in the coveted time slot for 32 years before stepping down at the end of last year.

McIvor has previously hosted Newstalk ZB's afternoon show with Mark Dye and last year hosted a Sunday morning show.

This year Smith starts a new weekly podcast, which will be recorded at NZME's studios.