The Australian Guineas at Flemington and the Randwick Guineas will again be run on the same day this season with officials saying there is no alternative.

The Australian Pattern Committee said despite efforts by Racing NSW and Racing Victoria the issue could not be resolved within the current programming constraints but the two bodies would continue to work towards a solution.

"The Pattern Committee believes that whilst the clash of the two Guineas is not ideal, there is no practical alternative at the present time," a statement said.

"Furthermore, the fact is that both races are feature events which easily met the designated benchmarks for Group One races in 2015 when they were run on the same day."

The committee has upgraded four of 16 eligible races from January 1 including the Guy Walter Stakes which goes from Group Three to Group Two.

Formerly known as the Wiggle Stakes, the race was renamed in 2015 to honour trainer Guy Walter who died suddenly last year.

The fillies and mares' race is part of Chipping Norton Stakes day at Warwick Farm, the track where Walter made his home and trained Group One winners including Tie The Knot, Spinning Hill, Appearance and Streama.

The other three races upgraded go from Listed to Group Three.

They are the Alexandra Stakes at Moonee Valley, the Blue Sapphire Stakes at Caulfield and the Festival Stakes at Rosehill.