A number of all-weather and National Hunt races will be removed from the British racing program in a bid to address small fields.

The British Horseracing Authority will scrap around 70 races on artificial surfaces which will be offset by nine additional all-weather twilight fixtures between September and October when field sizes are generally healthier.

Around 100 races over jumps are also set to be removed next year, with approximately 80 of those over fences.

The steeplechase program has expanded by more than 100 races since 2008, but in the same period the total number of runners over fences has decreased by over 1000.

"Set against a list of positive developments such as increased prize-money, healthy racecourse attendances and the exceptionally high quality of racing at the top end, small-field races have become arguably the biggest challenge facing British racing in recent years," BHA chief executive Paul Bittar said.

"Not only are they unattractive to punters and customers but they also reflect badly on British racing when compared with other major jurisdictions, at a time when racing is becoming an increasingly international sport.

"The increase in small-field races is the result of a decline in the number of horses in training of around 1600 since 2008, combined with an increase of around 650 races being added to the race program in this period."

There will also be a general restriction on the number of races per fixture, meaning all meetings must now consist of no more than seven races, apart from when a division of a particular race is appropriate.