Noticed a slight hesitancy which has now got to the point I need to get something done!
Oddly it runs fine from cold, but when I stop for say fuel or pop into a shop, then on the return journey a hesitancy has arisen (usually after coming off throttle) and has now progressed to the ignition warning light coming on.
Any ideas?
I'm looking to work through the probable causes?

Possibly an injector but if the injection warning light is on then you need to get the codes read.

What is your temperature gauge reading when the engine is fully warm? It should be 90-ish, whether driving or idling

Any less could mean your thermostat is sticking open, causing the engine to run cool, which in turn will cause over-fuelling, which could be a cause of hesitancy

I agree with GrahamL - get the codes read first - it'll confirm or eliminate lots of possible causes

Thanks both for the suggestions.
Had the codes read and it turned out to be a faulty throttle control regulator.
The drive over to Upton was a tad tricky as the throttle would stick open and the hesitancy got pretty bad.
Joe fitted a spare throttle control regulator and the trip back reminded me why I bought the car in the first place! She pulls like a train now!!!
Cheers Joe and thanks to all.