The divergence of SVR and Bank of England Base Rate became obvious in 2007. This was highlighted by Moneyfacts in its Mortgage Market Report published in early 2008.
Also SVR's have been creeping up for this last few months and as Minerva quite rightly points out this may well stimulate homeowners to remortgage as the SVR becomes less attractive.
I get the impression that banks really want to push Discounted Mortgages and Tracker Mortgages as these ensure they can maintain margin with minimal management and risk.
You might want to
read this article