Thanks for getting back to me. Sounds like some sort of statutory declaration would be the best way to proceed.
I have found four signed and dated employer references from the period, although there is a gap in the middle where I was working for cash and some travelling etc.
What sort of evidence do people normally supply with such applications?
I have a concern with the stat dec approach - I am working a timeline of the dates of when i left the country and returned etc but the dates are a bit of a guesstimate as I don't have exact records. I am worried that if i sign a stat dec saying i was in the country these days and that, is there a chance they obtain immigration control records which have different dates and hence the stat dec is wrong? There were some trips to France for a few days here and there for instance that I would have no idea on the dates....
Do you know if they access passport control records?