Some useful goverment guidance here.
www.gov.uk/.../guidance-on-shielding-and-protecting-extremely-vulnerable-persons-from-covid-19
The principle seems to be "even though shielding will be paused from 1 August, to let them work from home if possible. If it is not possible then they should return to work if the site is free of the Covid-19 virus........"

Hi
If they have received a letter from the government during the last 7-10 days confirming that they remain in the extremely vulnerable category then they must continue 'shielding' until 31st July and an employer cannot ask them to return earlier than 1st August.

However, a lot of those who originally received notification (back in March/April) of being in the extremely vulnerable category have recently been removed from that category and will have received a letter, again during the last 7-10 days, informing them of this.

I would therefore ask the employee for a copy of the letter they have received recently (not the one they will have originally received in March/April!)for your records.
Obviously, if the letter states that although originally on list of those deemed extremely vulnerable they are no longer considered to be so (based on what is now known about the virus) then they can return to work now.

What I would mention is that, for a lot of those that have been shielding for the past 3 months, the prospect of going from staying indoors for this length of time to going back 'into the world' can be quite daunting and a lot of employers are sympathetic to this and arranging for phased returns over a couple of weeks using the new CJRS rules allowing part time work to take place alongside furlough.

My interpretation is that until 1st August the Government have done the risk assessment and said stay at home
What they are now saying is that it is for employers and employees to do their own individual risk assessments. This means starting with your general ones and then agreeing what (if any) additional measures need to be instituted for them to protect and reassure.
I would start with Susan's suggestion of a copy of their letter/text.
Bear in mind there is a good chance they are disabled so you do at least have to consider reasonable adjustments and look reasonable.

In reply to Peter Stanway:

Peter thank you

In reply to Susan May:

Susan thanks so much for this.

In reply to Ray:

Ray thank you

In reply to Susan May:

The list of those 'shielding' is certainly not static. Originally, the Govt sent letters to 900,000 'vulnerable' people about the shielding policy, with another 600,000 informed by their GPs as they are not on a national register.

NHS England wrote to GPs and hospitals to review and update the list of shielded individuals and groups.

It does go up and down.

In reply to Steve Bridger:

Yes, one of my friends who has a son who was originally in the clinically extremely vulnerable group due to a liver transplant has now been told he doesn't need to shield any longer because of other factors such as his immune system being stable. So they are better able to assess the detail of who really needs to shield now as opposed to the broad brush approach that they used at the start.

In reply to Jacqueline:

Thanks Jacqueline

In reply to Steve Bridger:

Thanks Steve