when im driving and then slow towards a junction, when i start to accelerate the car starts to stutter and feels sluggish like there not enough power, ive just changed the fuel filter and still the same prob any ideas

I'd say clogged injectors, fine when you've been up to speed for a while but when you stop then go they don't supply the engine with enough fuel. Buy some INJECTOR CLEANER fluid from the garage, fill with a full tank and put half the bottle in with it.

Should fix your issue.

petrol or diesel?

petrol

First of all what model and engine size do you have, if you can check to see if there are any stored fault codes, if not check fuel pump pressure

First of all what model and engine size do you have, if you can check to see if there are any stored fault codes, if not check fuel pump pressure

always start with the cheaper tests first like using the injector fluid cleaning liquid, i had some in my deisel focus just to clean it out, just pop a little in then add no less then £10 of petty in =) if problem still accurs id do the dashboard trick for the fault code if ones logged then look up the fault area, or take it to a shop for a diagnostic check =) could be owt or nowt, not worth the worry yet =)

Your car lacks power maybe because your catalytic converter is partially plug. It might also be a problem of fuel or exhaust restriction. You also need to ensure that you have a throttle body spacer properly plugged.