The first four of England's five annual Classic horse races, including the Epsom Derby, have all been postponed due to the coronavirus it was announced Tuesday.
In a separate development, organisers of June's Royal Ascot said the meeting would not "take place as an event open to the public".
Course owners the Jockey Club said the Guineas Festival at Newmarket, featuring both the 1,000 and 2,000 Guineas on the first weekend of May and the Derby Festival, which was due to stage the Oaks and the Derby at Epsom on 5-6 June, had both been postponed in response to the outbreak.
"We are now working with our partners in the industry to seek to establish a future date when the Investec Oaks and the Investec Derby races can take place, and will keep you informed on any future developments," the Jockey Club said in a statement.
A similar statement was issued by the Jockey Club in respect of the Guineas meeting.
The Classics, all for three-year-olds and run over differing distances, with the 1,000 Guineas and the Oaks restricted to fillies, are some of the oldest and most prestigious in the global racing calendar.
With that in mind, the governing British Horseracing Authority (BHA) said the races would be central in their plans were they allowed to restart racing after suspending it last month in response to the spread of Covid-19.
"As a sport we have a responsibility to safeguard the staging of our Classics, and to position them within a sensible, balanced schedule of complementary events wherever possible," Ruth Quinn, the BHA's director of international racing and racing development told the BBC.
"Naturally one of the key priorities is the staging of the generation-defining races."
Another highlight of the English racing season is Royal Ascot, situated near Windsor Castle and long a favourite of Britain's Queen Elizabeth II, a noted horseracing enthusiast.
Staging major events without spectators is a prospect officials across all sports are contemplating following the spread of the coronavirus and Ascot chief executive Guy Henderson said: "It may prove possible to run the Royal Ascot races behind closed doors, dependent on government and public health policy and the approval of the BHA for us to re-start racing."
The St Leger, the fifth of English racing's five annual Classics, is traditionally run much later in the season in Doncaster, with this year's edition scheduled for 12 September.
Pinatubo, owned by the Godolphin team bankrolled by Dubai ruler Sheikh Mohammed's and trained in Newmarket by Charlie Appleby, had been favourite for both the 2,000 Guineas and the Derby.
All racing in Britain was suspended on 17 March in response to the spread of Covid-19 after the BHA were criticised for allowing that month's four-day Cheltenham Festival jumps meeting, which attracted more than 250,000 spectators, to go ahead.