Well, base rate is not going to get any lower so there's only one way to go and that is up.
However, all the forecasts I've seen suggest that base rates will stay low, probably at 0.5% for the next 18 months (I work in financial services and yes, am aware that this sector hasn't covered itselves in glory recently).
However, as seems likely if the Conservatives get in next year it depends what their monetary policy is and that could affect rates as they have in the past raised interest rates in response to an overheating economy although we are well past overheating and now looking to try and recover.
Fixed rates are always higher than SVR as there is an element of cover built in there for the lender so if base rate stays the same you are likely to be overpaying for the next 18 months.
My recommendation is to go for the best SVR you can find. Happy with my tracker rate of 0.66% above base for the time being.
Of course I am not qualified to give you investment advice and rates can go down as well as up. any losses you incur are your own tough sh*t. :wink:
BTW. I've had a mortgage since about 1986. Not claiming to be an expert but i've seen my fair share of fixed rates, SVR's, negative equity (1992'ish), base rate as high as 14% and everything in between.