The Dyke family has a lengthy relationship with the Wanganui Jockey Club dating back to 1963 through patriarch, the late Herbie Dyke, founder of Wanganui Motors. His sons, Steven and Simon, are both aghast at the proposed changes.
"Opposition to this proposal cannot be worded strongly enough or voiced loudly enough - it's lunacy," Steven Dyke told the Chronicle.
"This will test the loyalty of many sponsors, including us - and sponsors and becoming increasingly harder to find.
"Simon and I are enthusiastic sponsors of the Wanganui Guineas and recently increased our contribution to $10,000 per annum to honour the memory of our late father who loved our club."
Mr Dyke said they were keen to see the higher level group 3 racing return to Whanganui and, if it involved the Guineas, they would further increase their contribution.
"This absurd proposal to move a prestigious Saturday meeting to a Sunday will devalue both listed races and lose valuable sponsorship dollars," he said.
The Dyke family are also sponsors of the richest weight-for-age event on the New Zealand calendar, the group 1 $400,000 Herbie Dyke Stakes.
Mr Dyke urged people to make submissions to the Racing Board.
Wanganui Jockey Club operations manager Bret Field backed that call and said submissions could be made through the club website page - http://www.wjc.co.nz/media/save-our-saturday
"The Wanganui Guineas has been run on a Saturday since the late 1800s - it all appears a bit contradictory, really," Mr Field said.
"We have until late this month to make submissions and I would urge people to back us with comments or submissions by March 23."
Meanwhile, the trainers' association welcomed a reduction of Saturday meetings given the shortage of jockeys, but were concerned the proposed distribution was unfair, with Central Districts losing five Saturdays compared to one apiece for northern and southern clubs.
"Saturday race meetings provide the best opportunity for sponsorship, stakes and for owners to view their horses racing," the trainers' submission said.
"The cost of travelling to other regions for Saturday meetings is very expensive, not only for horses, trainers and their staff, but also for owners themselves.
"There are some meetings of importance in the Central Districts we believe should revert to Saturdays: September - the Wanganui Jockey Club has two black type races on the programme and a high quality support card with high turnover."
The trainers proposed the Central Districts have two Saturdays returned to the calendar and one each taken from northern and southern clubs.
The owners' federation echoes the trainers' concerns.
The Saturday spring meeting at Wanganui - which last year produced turnover of $120,736 on-course, and $948,621 off-course - goes head-to-head with a strong northern meeting substantially increasing inter-track betting. Changing to a Sunday, where it would be up against a lower grade southern fixture, inter-track turnover plummets.
The Racing Board's own guidelines suggest black type races should be held on Saturdays.