The Waratahs have emerged as a shock rival to the Wallabies in the race for the signature of respected New Zealand coach Dave Rennie.

The Herald understands NSW Rugby Union figures have reached out to gauge Rennie's availability to take over from departing coach Daryl Gibson, who resigned last month with a year left on his contract.

The audacious move pits NSW directly against Rugby Australia, who want the UK-based Kiwi to coach the Wallabies when Michael Cheika steps down, as expected, after the upcoming Rugby World Cup.

Success story: Dave Rennie is with Glasgow after winning two Super Rugby titles with the Chiefs. Credit:EPA

Rennie's current deal could decide the winner in that contest, if it hasn't already been decided, as Herald sources suggest. The former coach of the Chiefs, who helped lead them to their first two Super Rugby titles, only recently signed a one-year extension with the Glasgow Warriors.