They will have the task of tracking down those who have been in contact with someone who has tested positive for the virus.

Our health editor, Hugh Pym, has the latest for millions of people.

A scheme in place today might make a big difference to their lives that they don't know it yet potentially, they could be told they've met up with someone recently who now has the virus, and they'll have to self isolate for two weeks, even if they're not ill.

They could find out through an email or text or phone call on then be asked to get in touch with the NHS From now on, if you are told you have been exposed to an infected person, you must self isolate for 14 days.

They'll hear that from contact traces.

25,000 of them will do the job in England, and as their task began, they received a video message from the health secretary, Matt Hancock.

We can't do any of this without you, and working together were part of one big team delivering the service in the days and weeks ahead.

The advice that you give on the support that you offer will make a difference to the lives off everybody who you speak to new contact.

Traitors have Bean signed up and trained, and they'll work with health professionals, some of whom already have experienced talking to patients with infectious diseases and then trying to find out who they may recently have met up with.

Whether you're used to going through a detailed account of UAL movements that must 79 days, we use diaries.

We use Tuesday's of the week.

Will weather was like to help people remember We're used to doing that and will continue to do that.

I think this is doable.

But one contact tracer, who wanted to remain anonymous, told us she couldn't log onto the system and so couldn't start today.

I was told that system waas not even yet ready to start.

The guy told me that so far they have a start date for next Monday, but not before that.

At that moment, I already thought, well, that is quite disappointing.

Other contact Trace has also struggled to log in This morning, the Department of Health acknowledged there had been problems but said these were being rapidly resolved, The systems being formally launched today.

But it's not yet clear how many people have so far been contacted.

Officials have acknowledged it may take a week or two for the system to be working at its full capacity.

Cubin BBC News Our medical correspondent, Fergus Walsh, is with me now, so restrictions are being eased again.

But there is clearly nervousness about what could happen next.

There is Sophie into pantry.

Valence, the chief scientific adviser, said that we are in a very fragile state on there's very little room for maneuver.

We have to be cautious.

So a lot of nervousness there and it's all down to the our number, this rate of infection.

This is the average number of people that each infected person will pass the virus on to.

Now, with Corona virus with no social distancing measures, that number is around three.

You quickly lead to a doubling on a redoubling of cases every few days, so the lock down is about bringing down those that are to below one on The latest estimate has been over the past two months.

We've now brought it down to somewhere between North 20.7 and not 0.9.

Now that is perilously close to getting above one when the outbreak could get out of control again on it's estimated that around 93 in 100 people in England have not yet had Kobe 19.

Around 500 people a day are still being admitted to hospital in England alone, well down on the more than 3000 today in early April.

But the threat is still there, Fergus.

Thank you.

And if you want more information on the measures announced today and the tracing systems that have been put in place, you can find the details at BBC dot co dot UK forward slash news forward slash corona virus and then click on the links.