Taxpayers face an even greater slug for Barnaby Joyce's relocation of a Canberra public service agency to the heart of his own electorate, with desperate bosses at the pesticides authority considering pay rises of up to 15 per cent in order to convince staff not to quit.

The pay rises would come on top of a 1.5 per cent retention bonus for workers still with the Australian Pesticides and Veterinary Medicines Authority in December 2017, a 3 per cent bonus if they remain on the books until December 2018 and a 10 per cent if they are still around when the Canberra office shuts in mid-2019.

Up to 12 free return flights a year between Canberra and Armidale are also being considered as an inducement for workers at the APVMA if they agree to make the move from their homes in and around the capital, 800 kilometres north to the northern NSW town.

Fairfax revealed this month that only 10, at most, of the APVMA's regulatory scientists were prepared to make the move to New England, the electorate of Deputy Prime Minister Mr Joyce, who is also Agriculture Minister.