Foreign-trained runners will only be allowed to compete in the Coronation Cup, 2000 Guineas and 1000 Guineas on the initial resumption of racing in Britain.
The British Horseracing Authority is planning for a restart of the sport behind closed doors on June 1, subject to Government approval, with the last fixtures to have been held in Britain being at Wetherby and Taunton on March 17.
Moved from Epsom this year, the Coronation Cup is due to be run at Newmarket on June 5, with the 2000 Guineas on June 6 and the 1000 Guineas on June 7.
In clarifying its position, the BHA said that discussions with the Flat Pattern Committee, together with France and Ireland, had been held in what was a “rapidly developing situation internationally”.
A statement read: “These discussions have been held against the backdrop of an overriding desire to see racing resume in Britain as soon as possible, with all the necessary protocols in place, such that we can ensure that racing can continue and ultimately revert to its pre-agreed programme.
“Should racing resume on this date, it is agreed that protecting ourselves against unnecessary risk in the opening few weeks is a responsible and proportionate approach.
“As a result, foreign-trained runners will only be permitted to run in the three Group One races taking place in Britain during the first fortnight, in order to help facilitate a safe and smooth resumption.
“International runners will not be permitted to take part in Group Two, Three or Listed races during this period, but will be able to participate in all Pattern and Listed races taking place in Britain from June 15 2020 onwards.”
The statement added: “Furthermore, no internationally-trained horses will be permitted to take part in any races of Class 2 and below until further notice. This step has been taken to help address concerns that with a reduced fixture list in place, the number of eliminations is likely to be a significant issue when racing resumes.
“This position will be kept under review and revisited as soon as circumstances allow.”
Irish champion trainer Aidan O’Brien has won the last three runnings of the 2000 Guineas and three of the last four renewals of the 1000 Guineas. O’Brien is also the leading trainer in the Coronation Cup with eight victories.
In a separate development, the Brigadier Gerard Stakes pencilled for Newmarket on June 5 will now be held at Haydock on June 7.