These answers to a similar query may help.
http://www.theanswerbank.co.uk/Business-and-Fi nance/Question713693.html
Bear in mind there may be a penalty to pay for paying off your mortgage early.
I agree that getting rid of savings can help with DWP benfit claims. On the other hand, if you are claiming benefits isn't some help with mortgage interest available after a period? If so, you need to take that into account.
Depending on your age and tax band it may be worth paying a lump sum into your pension.