The answer is simple - show your employer that you are too valuable to lose  and that you are worth that little extra.

Lucy McGee of global human resources consultancy DDI believes that providing evidence is vital. "You must describe what you have been involved in, explain your actions and the result," she says.

"The closer you can get to quantifying the outcome in numbers, the more successful you are likely to be. It could be worth an extra £3,000 a year."

But there is a ceiling to these discretionary rises, fixed by the pay limits for individual grades. If you want to earn more than that limit, you should seek promotion.

Eric McDonogh, a project co-ordinator with payroll systems provider Snowdrop Systems, joined the Oxford company three years ago as a graduate and was promoted to team leader in February.

Eric, 25, from Oxford, says: "I volunteered to take on parts of the team leader's role and became more involved in more complicated client projects. I also asked my line manager what skills I needed to improve and be considered for promotion."