England will be limited to selecting squads of 28 players for their Guinness Six Nations title defence in an effort to enhance coronavirus safety measures.
The Rugby Football Union has struck an agreement with Premiership Rugby and the Rugby Players' Association that enables the 28 to remain in camp for the entirety of a Test week.
It was previously customary for head coach Eddie Jones to pick an initial training squad of around 32 players that would arrive in camp on a Monday.
This would then be trimmed to a smaller group of 23 to 25 on a Tuesday or Wednesday night, enabling those not in contention to play for England that weekend to turn out for their clubs instead.
But now the larger group of 28 will be kept for the whole week to help protect the bubble environment. Last autumn, players had to be brought in from Harlequins to make up the numbers in training.
"In recognition of the challenges presented by Covid-19, Premiership Rugby, the RPA and the RFU have agreed that England will retain a 28-player squad," an RFU statement read.
"This will reduce movement in and out of the England team environment."
The development comes after French Rugby Federation president Bernard Laporte said players would now be tested twice a week in response to fears from the French government over Les Bleus taking part in the Six Nations.
So far, France have been given clearance to play their opening match against Italy on 6 February but not for the trips to Dublin and London.
England launch their title defence against Scotland at Twickenham on the same day and will spend the first week of their build-up at St George’s Park, the Staffordshire training base used by England’s football team.
From there they will head to The Lensbury in south west London where they will be located for the remainder of the Six Nations, having been camped there for the whole of the Autumn Nations Cup.