Does changing current accounts hit your credit rating?

I'd like to move from Barclays to First Direct for reasons of interest rates, service quality etc. If I then apply for a loan, mortagage, credit card etc which depends on a credit check, will my score be adversely affected by having had my current account for a few months (as opposed to 20 years as is presently the case)? If so, should I leave my Barclays account open but inactive, or is it better to close it if I'm not using it?