Colleges spent at least £65 million on agency staff during the last financial year, according to information obtained by Unison.
The trade union has calculated a combined bill of £64,613,485 for 170 colleges through freedom of information requests.
The disclosure, which details spending between August 2010 and July 2011, follows plans for potential redundancies at a number of FE colleges across the country, as revealed in FE Week last month.
Unison say using agency workers is “a disgraceful waste of money”, and colleges should be using their resources to either protect jobs or improve wages.
Jon Richards, head of education at Unison, said: “Colleges are claiming that they cannot afford to relieve the pressure on workers and their families by giving them a pay rise.
“These staff will be rightly shocked that colleges have tens of millions to spend on agency workers and on VAT bills.”
Mr Richards added: “It is time for colleges to stop wasting money and manage their budgets so they can pay workers fairly and safeguard jobs.”
While Leeds City College appears at the top of the table, it is important to look at these figures in context.”
Leeds City College, who spent a total of £2,777,628 on agency workers in 2010/11, came out highest in the information gathered by Unison.
However, the college told FE Week it is common practice to employ external contractors and consultants.
A statement from the college reads: “It is imperative for the college to be able to fulfil its key function of teaching and learning – and due to a number of factors (for example maternity cover, staff absences as a result of illness), there may be the requirement for the use of highly specialised academic or business support personnel for short specific periods of time and/or projects.”
It later adds: “While Leeds City College appears at the top of the table, it is important to look at these figures in context.
“Leeds City College is the third largest FE college in the country and any additional temporary spend is likely to be numerically greater than that of most other colleges.
“In 2010/11, the College had an annual turnover of £80 million, with more than 45,000 students over multiple sites.
“College agency spend highlighted is the equivalent of 3.4% of total turnover.”
Rotherham College of Arts and Technology, which spent £2,214,529 on agency workers in 2010/11, has also defended the practice and says it helps them to quickly respond to learner needs.
Gill Alton, principal and chief executive of the college, told FE Week: “We use agency staffing as a part of our overall staffing mix.
“It enables us to respond flexibly to changes in student demand but also funding changes, of which there are a lot in further education at the moment.”
Unison say agencies regularly charge “as much as three times” what they would for a permanent member of staff, and also have to pay 20 per cent VAT on agency bills.
Evan Williams, director of employment and professional services at the Association of Colleges said: “Colleges, which are independent organisations, are aware of the financial benefits and implications of employing agency staff, but it is not always easy to fill these specialist positions often leaving the institutions with few alternatives. It is up to colleges to best channel resources to account for these conditions and they are always looking to be prudent.
“It is a more complicated issue that requires an all-round approach to maintain quality provision.”