I suspect the lower wishbone bushes are worn...my mk5 escort diesel van did exactly the same thing and I guess ya pug has a similar suspension setup...
Wishbone bushes when worn allow one wheel to drag forwards and hence turn slightly under acceleration and then return to normal place when throttle is eased off...
Unfortunately tracking checks wont reveal the problem, will read fine, unless you can find a brave mechanic who will check it when you are a full throttle!
Hope this helps matey...