tony's reply makes sense to me. In my line of work, employers often ask employees to sign something like that - the reason being, why should employer 1 fork out several thousand pounds for a required NVQ, only to find that the person uses the qualification to go and find a better job, for the benefit of another employer. Some employers in fact say that because that level of NVQ is a requirement of the job, the employee has to contribute, or doesn't receive the full grade salary until they have attained that qualification.
It's dodgy ground IMO and it really does depend what the training clauses are in her her contract of employment.
There is a school of thought which thinks this isn't legally binding but I understand it has been challenged and the employer won.
http://www.justanswer...g-pay-back-fee-s.html
However - I really think your wife ought to contact someone impartial like ACAS about this - which is free
http://www.acas.org.u...x.aspx?articleid=1390
The accepted answer on this link is quite helpful