The National Archives have just released the Poor Law and Workhouse Records for free access on their website.
http://www.nationalarchives.gov.uk/docu ... khouse.asp
You can download records of the Poor Law Unions listed below. All the records start at 1834, the year of the Poor Law Amendment Act.
Axminster Poor Law Union, Devon and Dorset, 1834- 1848
Basford Poor Law Union, Nottinghamshire and Derbyshire, 1834- 1845
Berwick upon Tweed Poor Law Union, Northumberland, 1834- 1852
Bishop’s Stortford Poor Law, Union Hertfordshire and Essex, 1834- 1852
Blything Poor Law Union, Suffolk, 1834-1840
Bromsgrove Poor Law Union, Worcestershire, 1834-1842
Cardiff Poor Law Union, Glamorganshire, 1834- 1853
Clutton Poor Law Union, Somerset, 1834- 1853
Keighley Poor Law Union, Yorkshire West Riding, 1834- 1855
Kidderminster Poor Law Union, Worcestershire, 1834- 1849
Liverpool Vestry (technically not a Poor Law Union, it retained vestry status throughout the 19th century), 1834- 1856
Llanfyllin Poor Law Union, Montgomeryshire and Denbighshire, 1834-1854
Mansfield Poor Law Union, Nottinghamshire and Derbyshire, 1834- 1849
Mitford and Launditch Poor Law Union, Norfolk, 1834- 1849
Newcastle under Lyme Poor Law Union, Staffordshire, 1834- 1856
Newport Pagnell Poor Law Union, Buckinghamshire, 1834- 1855
Reeth Poor Law Union, Yorkshire North Riding, 1834- 1871
Rye Poor Law Union, East Sussex and Kent, 1834- 1843
Southampton, Hampshire (technically not a Poor Law Union but an earlier incorporation), 1834- 1858
Southwell, Nottinghamshire, 1834- 1871
Truro Poor Law Union, Cornwall, 1834- 1849
Tynemouth Poor Law Union, Northumberland, 1834- 1855
Wolstanton and Burslem Poor Law Union, Staffordshire, 1834- 1851