I went to a talk this morning given by Peter Higginbotham that was very interesting and informative, and he highlighted to me two sources of information that I was previously unaware of.

Firstly in 1861 the Govt ordered a list to be drawn up of every adult inmate in England & Wales who had been in a workhouse for more than 5 years and why. That list is now on Ancestry- "long term workhouse inmates" in their wills, tax and land section, rather than in the census section. You can search by name, but you can browse as it's not, a large document thats easy to do.

The other source is the "religious creed register" that all workhouse kept. These if they have survived give details of where the inmate was living before entering the workhouse and known next of kin. If they have survived they will be in the record office that holds the workhouse records.