Hi,
Is your mortgage term coming to an end, or just the 'fixed' part of it?
In your current mortgage term is not coming to an end, you may be lucky enough to be going onto the standard variable rate, which may be lower than any available fixes or other deals.
If your term is coming to an end it is more difficult.
In general terms the lowest mortgage companies generally offer in a mortgage (rather than a loan) is £25,000, but you should be able to discuss this further with your mortgage lender.
Also if you are coming to the end there are other costs (fees) involved and not just the capital, so it is good to get a settlement figure from the bank to confirm how much it would actually cost to settle the debt.
I hope this helps.
Sparky.
PS I'm only an enthusiast, not a Financial professional.