In reply to Mark Edwards:
I've been taking part in the ONS Infection Survey for the last couple of months. I'd hoped to be able to blag a free antibody test, but the first couple of surveyors suggested that this wasn't offered any more. One of the questions they ask is 'do you think you've had Covid before?'. I answered that I might well have done, citing a couple of instances, but I don't know for sure as I wasn't tested at the time. To which they put 'no' as the answer, as I couldn't be sure. I went round in circles with them a few times with this. A bit of a silly question really, as they then go on to ask you if you've ever tested positive.
You will get a self-administered PCR swab test. They don't use the LFT for the ONS survey.
If you did have Covid at the beginning of last year, you probably wouldn't have detectable antibodies anymore, as they recede after 2-3 months.
It has also been taking me over a week to receive the results (they are not prioritised, as you are not being tested as a suspected case). So if you think you may get the benefit of regular free screening, forget it. The vouchers start coming through after 3-4 weeks.
It's good to feel that I am contributing to a statistically sound study anyway.